patch 8.2.3069: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move some error messages to errors.h.  Use clearer names.
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 027d139..62d50b2 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -1997,7 +1997,7 @@
 	    }
 
 	    if (ea.line2 < 0)
-		errormsg = _(e_invrange);
+		errormsg = _(e_invalid_range);
 	    else
 	    {
 		if (ea.line2 == 0)
@@ -2124,7 +2124,7 @@
 	if (!curbuf->b_p_ma && (ea.argt & EX_MODIFY))
 	{
 	    // Command not allowed in non-'modifiable' buffer
-	    errormsg = _(e_modifiable);
+	    errormsg = _(e_cannot_make_changes_modifiable_is_off);
 	    goto doend;
 	}
 
@@ -2134,7 +2134,7 @@
 	    if (cmdwin_type != 0 && !(ea.argt & EX_CMDWIN))
 	    {
 		// Command not allowed in the command line window
-		errormsg = _(e_cmdwin);
+		errormsg = _(e_invalid_in_cmdline_window);
 		goto doend;
 	    }
 #endif
@@ -2996,7 +2996,7 @@
 				{
 				    if (tabnr < 0 || tabnr > LAST_TAB_NR)
 				    {
-					*errormsg = _(e_invrange);
+					*errormsg = _(e_invalid_range);
 					return FAIL;
 				    }
 				    cmod->cmod_tab = tabnr + 1;
@@ -3239,14 +3239,14 @@
 			{
 			    // there is no Vim command which uses '%' and
 			    // ADDR_WINDOWS or ADDR_TABS
-			    *errormsg = _(e_invrange);
+			    *errormsg = _(e_invalid_range);
 			    return FAIL;
 			}
 			break;
 		    case ADDR_TABS_RELATIVE:
 		    case ADDR_UNSIGNED:
 		    case ADDR_QUICKFIX:
-			*errormsg = _(e_invrange);
+			*errormsg = _(e_invalid_range);
 			return FAIL;
 		    case ADDR_ARGUMENTS:
 			if (ARGCOUNT == 0)
@@ -3278,7 +3278,7 @@
 		// '*' - visual area
 		if (eap->addr_type != ADDR_LINES)
 		{
-		    *errormsg = _(e_invrange);
+		    *errormsg = _(e_invalid_range);
 		    return FAIL;
 		}
 
@@ -3923,7 +3923,7 @@
     if (addr_type == ADDR_NONE)
 	emsg(_(e_norange));
     else
-	emsg(_(e_invrange));
+	emsg(_(e_invalid_range));
 }
 
 /*
@@ -4210,7 +4210,7 @@
 		    i = RE_SEARCH;
 		else
 		{
-		    emsg(_(e_backslash));
+		    emsg(_(e_backslash_should_be_followed_by));
 		    cmd = NULL;
 		    goto error;
 		}
@@ -4312,7 +4312,7 @@
 
 	    if (addr_type == ADDR_TABS_RELATIVE)
 	    {
-		emsg(_(e_invrange));
+		emsg(_(e_invalid_range));
 		cmd = NULL;
 		goto error;
 	    }
@@ -4460,7 +4460,7 @@
     if (       eap->line1 < 0
 	    || eap->line2 < 0
 	    || eap->line1 > eap->line2)
-	return _(e_invrange);
+	return _(e_invalid_range);
 
     if (eap->argt & EX_RANGE)
     {
@@ -4472,46 +4472,46 @@
 			    + (eap->cmdidx == CMD_diffget)
 #endif
 		   )
-		    return _(e_invrange);
+		    return _(e_invalid_range);
 		break;
 	    case ADDR_ARGUMENTS:
 		// add 1 if ARGCOUNT is 0
 		if (eap->line2 > ARGCOUNT + (!ARGCOUNT))
-		    return _(e_invrange);
+		    return _(e_invalid_range);
 		break;
 	    case ADDR_BUFFERS:
 		// Only a boundary check, not whether the buffers actually
 		// exist.
 		if (eap->line1 < 1 || eap->line2 > get_highest_fnum())
-		    return _(e_invrange);
+		    return _(e_invalid_range);
 		break;
 	    case ADDR_LOADED_BUFFERS:
 		buf = firstbuf;
 		while (buf->b_ml.ml_mfp == NULL)
 		{
 		    if (buf->b_next == NULL)
-			return _(e_invrange);
+			return _(e_invalid_range);
 		    buf = buf->b_next;
 		}
 		if (eap->line1 < buf->b_fnum)
-		    return _(e_invrange);
+		    return _(e_invalid_range);
 		buf = lastbuf;
 		while (buf->b_ml.ml_mfp == NULL)
 		{
 		    if (buf->b_prev == NULL)
-			return _(e_invrange);
+			return _(e_invalid_range);
 		    buf = buf->b_prev;
 		}
 		if (eap->line2 > buf->b_fnum)
-		    return _(e_invrange);
+		    return _(e_invalid_range);
 		break;
 	    case ADDR_WINDOWS:
 		if (eap->line2 > LAST_WIN_NR)
-		    return _(e_invrange);
+		    return _(e_invalid_range);
 		break;
 	    case ADDR_TABS:
 		if (eap->line2 > LAST_TAB_NR)
-		    return _(e_invrange);
+		    return _(e_invalid_range);
 		break;
 	    case ADDR_TABS_RELATIVE:
 	    case ADDR_OTHER:
@@ -4521,14 +4521,14 @@
 #ifdef FEAT_QUICKFIX
 		// No error for value that is too big, will use the last entry.
 		if (eap->line2 <= 0)
-		    return _(e_invrange);
+		    return _(e_invalid_range);
 #endif
 		break;
 	    case ADDR_QUICKFIX_VALID:
 #ifdef FEAT_QUICKFIX
 		if ((eap->line2 != 1 && eap->line2 > qf_get_valid_size(eap))
 			|| eap->line2 < 0)
-		    return _(e_invrange);
+		    return _(e_invalid_range);
 #endif
 		break;
 	    case ADDR_UNSIGNED:
@@ -5187,7 +5187,8 @@
     if (secure)
     {
 	secure = 2;
-	eap->errmsg = _(e_curdir);
+	eap->errmsg =
+	      _(e_command_not_allowed_from_vimrc_in_current_dir_or_tag_search);
     }
     else if (eap->cmdidx == CMD_autocmd)
 	do_autocmd(eap->arg, eap->forceit);
@@ -5842,7 +5843,7 @@
     {
 	if (unaccept_arg0 && eap->line2 == 0)
 	{
-	    eap->errmsg = _(e_invrange);
+	    eap->errmsg = _(e_invalid_range);
 	    tab_number = 0;
 	}
 	else
@@ -5852,7 +5853,7 @@
 	    {
 		--tab_number;
 		if (tab_number < unaccept_arg0)
-		    eap->errmsg = _(e_invrange);
+		    eap->errmsg = _(e_invalid_range);
 	    }
 	}
     }
@@ -6564,7 +6565,7 @@
 		    tab_number = eap->line2;
 		    if (tab_number < 1)
 		    {
-			eap->errmsg = _(e_invrange);
+			eap->errmsg = _(e_invalid_range);
 			return;
 		    }
 		}
@@ -7715,7 +7716,7 @@
      */
     if (n == MAXLNUM || n < 0 || n > curbuf->b_ml.ml_line_count)
     {
-	emsg(_(e_invrange));
+	emsg(_(e_invalid_range));
 	return;
     }
 
@@ -8163,7 +8164,7 @@
     // with Unix it is possible to open a directory
     if (mch_isdir(fname))
     {
-	semsg(_(e_isadir2), fname);
+	semsg(_(e_src_is_directory), fname);
 	return NULL;
     }
 #endif