The composer.lock file belongs to the repository. Do not ignore.
Remove all ignores that belong to users global .gitignore file.
Only apply git ignores relative to repository root.
Merge pull request #184 from bantu/gitignore-cleanup

Gitignore cleanup
Merge branch 'master' into php5

* master:
  Only apply git ignores relative to repository root.
  Remove all ignores that belong to users global .gitignore file.
  The composer.lock file belongs to the repository. Do not ignore.