Delete .hgignore
Merge pull request #143 from Hello71/hgignore

Delete .hgignore
add material placeholder for more jobs
Use qmake builtin debug_and_release.
Remove OS-specific entries from .gitignore.

.gitignore should only store items that are generated by the code in the
repository. If your operating systems generates temporary files, put
those in your .gitignore_global.