Add a README.md

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge pull request #115 from msysgit/tip4commit

Mention tip4commit
Enable Python by default on MINGW
Convert charactor encoding to utf-8 on MINGW before git fast-import

System default in Japanese Language version
 * p4: CP932 on Windows
 * msysgit: UTF-8 on Windows(MINGW)
Cosmetic change
Improve conversion of character encoding

- Make use of P4CHARSET environment variable
- Make use of encode method with ignore option
Merge branch 'feature/git-p4-onWindows-Spike' of https://github.com/tota/git into git-p4-onWindows-Spike