updated for version 7.4.234
Problem:    Can't get the command that was used to start Vim.
Solution:   Add v:progpath. (Viktor Kojouharov)
diff --git a/src/eval.c b/src/eval.c
index d9785c4..246e404 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -361,6 +361,7 @@
     {VV_NAME("hlsearch",	 VAR_NUMBER), 0},
     {VV_NAME("oldfiles",	 VAR_LIST), 0},
     {VV_NAME("windowid",	 VAR_NUMBER), VV_RO},
+    {VV_NAME("progpath",	 VAR_STRING), VV_RO},
 };
 
 /* shorthand */