README: Git for Windows is currently switching to the Git for Windows SDK

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Remove the dysfunctional link to tip4commit

Due to the lack of donations, tip4commit removed us from their list.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge pull request #285 from dscho/readme

Update README.md
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
Add URLs to refer to character encodings

 * http://www.perforce.com/perforce/doc.current/user/i18nnotes.txt
 * http://docs.python.org/2.7/library/codecs.html#standard-encodings
Improve conversion of character encoding when p4 submit

- Convert character encoding of logMessage to P4CHARSET or to a encoding
  from user preferences, appropriately
- Separate p4char2encode hash from tounicode function, accordingly
- Use the Codec instead of Aliases in Python Standard Encodings

https://docs.python.org/2.7/library/codecs.html#standard-encodings
- Distinguish decoded data and data
- Make debug print conditionally
Ignore error in marshaled data if Perforce file type is utf16

The value of "code" in marshaled data is often "error", which is
"CANNOT TRANSLATE" error message [1] with "p4 -G -x - print",
if Perforce file type is utf16. But the missing data will be handled properly
in the streamOneP4File method with "p4 print -o".

  [1]
  Internationalization Notes for P4D, the Perforce Server and Perforce
  client applications
  http://www.perforce.com/perforce/doc.current/user/i18nnotes.txt