adding a few files for editing VCtools conf files
refactor of vimS (and related tweaks)

vimS will now cd to the proper dir first
better use of eval
easier to add more prefixes if necessary
most importantly: vimS -l will list possible session files)
-	(will allow me to do auto-complete, finally)
also added a "cd" to one session file that didn't have it
also changed "bad_arg" (in bash_funcs) to "usage_error" (what was I smoking?)
new session file for VCtools stuff