minor error message improvements
Merge pull request #3580 from WalterBright/err-msgs

minor error message improvements
Add posix.mak itself as dep
First import toks documented
More docs
Add -query=OFFSET flag
Use query offset
Fixes
Remove empty line
Fixes
Add more feedback
Add query flag comment
Parse row and column arguments to -query flag
Improve comment
Fix merge conflicts
Solve
Bail when passed query position
Add more descriptions
Add For Debugging Descriptions
Hint works anywhere on token