1377 - Blacklist dependencies from SCM tracking

Git excludes dependencies from commit. 
Mercurial just shows a warning because it doesn't support excludes on commits. Just hgignore
"This will fail on Windows - you are opening a file for writing that is still open for reading, file locking won't allow it. You should really only open this file once, file mode "r+" - this will allow you overwriting the file contents after reading it."