Fixed vp_kill; kill pgid only if pid == pgid
Merge pull request #170 from ichizok/fix-vp_kill

Fix vp_kill
[WIP] Enable to specify mode characters to vimproc#fopen()
[WIP] Changed vimproc#fopen() caller argument
[WIP] Moved string-to-oflag convertion to C code
[WIP] Changed windows oflags; add leading underscore
[WIP] Modified vimproc#fopen help description
[WIP] Fixed missing variable