MSYS branch: get /.gitignore from master branch

As requested in [#190](../issues/190#issuecomment-40872606):

Get `.gitignore` from 13744e0412652f497a5a79283a24e54aa630a00d (latest change of the file on the 'master' branch) and push it on msys branch. Cherry-picking was not possible because the commits concerned other files than .gitignore.