Cleanup -vgc implementation
Merge pull request #3405 from jpf91/cleanVGC

Cleanup -vgc implementation
Add posix.mak itself as dep
Add -Wall and -Wextra warnings to posix.make
Add better warnings still
First import toks documented
More docs
Add -query=OFFSET flag
Use query offset
Fixes
Correction
Remove empty line
Fixes
Add more feedback
Add query flag comment
Parse row and column arguments to -query flag
Improve comment
Error handling
Works at beginning of token
Bail when passed query position