patch 8.1.0418: MS-Windows: cannot separate Lua include and library dirs

Problem:    MS-Windows: cannot separate Lua include and library directories.
Solution:   Add LUA_LIBDIR and LUA_INCDIR. (Ken Takata, closes #3464)
diff --git a/src/Make_cyg_ming.mak b/src/Make_cyg_ming.mak
index b9ce390..7b9c745 100644
--- a/src/Make_cyg_ming.mak
+++ b/src/Make_cyg_ming.mak
@@ -244,6 +244,8 @@
 
 #	Lua interface:
 #	  LUA=[Path to Lua directory] (Set inside Make_cyg.mak or Make_ming.mak)
+#	  LUA_LIBDIR=[Path to Lua library directory] (default: $LUA/lib)
+#	  LUA_INCDIR=[Path to Lua include directory] (default: $LUA/include)
 #	  DYNAMIC_LUA=yes (to load the Lua DLL dynamically)
 #	  LUA_VER=[Lua version, eg 51, 52] (default is 53)
 ifdef LUA
@@ -256,7 +258,8 @@
 endif
 
 ifeq (no,$(DYNAMIC_LUA))
-LUA_LIB = -L$(LUA)/lib -llua
+LUA_LIBDIR = $(LUA)/lib
+LUA_LIB = -L$(LUA_LIBDIR) -llua
 endif
 
 endif
@@ -524,7 +527,8 @@
 endif
 
 ifdef LUA
-CFLAGS += -I$(LUA)/include -I$(LUA) -DFEAT_LUA
+LUA_INCDIR = $(LUA)/include
+CFLAGS += -I$(LUA_INCDIR) -I$(LUA) -DFEAT_LUA
 ifeq (yes, $(DYNAMIC_LUA))
 CFLAGS += -DDYNAMIC_LUA -DDYNAMIC_LUA_DLL=\"lua$(LUA_VER).dll\"
 endif
diff --git a/src/version.c b/src/version.c
index 1a6b94d..079657e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -795,6 +795,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    418,
+/**/
     417,
 /**/
     416,