nvie/gitflow — pull request #161 by mhart (2011-10-16 06:15:48+00:00)
Title: Added check for MinGW environment so that we can fix windows paths

After a recent installation of msysGit (Git-1.7.7-preview20111014.exe), I've found that the path seems to be getting mangled when invoking git-flow, and the following error occurs:

```sh
$ git flow init
C:\Program Files (x86)\Git\bin\git-flow: line 68: ./gitflow-common: No such file or directory
C:\Program Files (x86)\Git\bin\git-flow: line 76: ./gitflow-shFlags: No such file or directory
```

This turns out to be because the `GITFLOW_DIR` variable is created by using `dirname $0` and `$0` in this case happens to be a Windows path with backslashes, and so the command just returns '.' instead of the actual path to Git.

This patch checks to see if we're in an msysGit environment and if so converts the path accordingly.