Update to 6.4

* Remove included patches.

Changelog:
Mew 6.4 stable release (2011/10/19)

* cmew falls back to getModificationTime on Windows.
Masamichi HOSODA <trueroad>
* Supporting Ruby 1.9.
Takahiro Kambe <taca>

Mew 6.4 release candidate 1 (2011/09/06)

* A bug of rescan is fixed finally!
* mewl avoids causing error if a folder does not exist.
Masamichi HOSODA <trueroad>
* Catching up to stunnel 4.39.
Ryo ONODERA <ryo_on>
* Supporting text/csv.
Tetsuya Toda <toda>

Mew 6.3.51 (2011/06/29)

* A hack for calling browser on Unix.
"Diogo F. S. Ramos" <diogofsr> and Tatsuya Kinoshita <tats>
* Bug fixes for hankaku.
<tmurata> and Tatsuya Kinoshita <tats>
* Avoiding broken end-of-line for quoted-printable.
* Multibyte hack for Emacs 23 and 24.
* Supporting GBK.
* Fixing excel and powerpoint on Unix.
Kan Sasaki <sasaki@fcc.ad.jp>
* pdftotext support for Windows.
Shuichi KITAGUCHI <ki>
* &rest to mew-user-agent-compose for Emacs 24.
Harald Hanche-Olsen <hanche>
* More gentle for broken Multipart/Signed.
Eisaku YAMAGUCHI <eisaku>
* Improving the documentation of mew-draft-use-format-flowed.
Christophe TROESTLER <Christophe.Troestler>
* varsx hack.
* Fixing regex of time.
Christophe TROESTLER <Christophe.Troestler>
* Fixing major mode hooks.
Hayashi Masahiro <mhayashi1120>
* Inline display of PDF with "pdftotext".
Hideyuki SHIRAI <shirai>
Harumitsu YOSHITAKE <yositake>
* Text/Pdf for Thunderbird
Christophe TROESTLER <Christophe.Troestler>
* Removing warnings for Emacs 23.3
Yu-ji Hosokawa <yu-ji>
* Killing stunnel with -KILL since the spec of stunnel changed.
* The -b option for mewest.
"Diogo F. S. Ramos" <diogofs>

Mew 6.3.50 (2010/08/31)

* Defining mew-draft-use-format-flowed.
Christophe TROESTLER <Christophe.Troestler>
* Making use of mew-save-dir.
* Fixing the hash-vs-array problem of cmew.
Masamichi HOSODA <trueroad>
* Making cmew safer in the case where mewest works at the same time.
Masamichi HOSODA <trueroad>
* Hack for mew-time-rfc-to-sortkey.
Hideyuki SHIRAI <shirai>
* A patch for unzip.
Yu-ji Hosokawa <yu-ji>
* Supporting unzip.
* Bug fix for PGP/MIME of binary encryption.
Shoichi Kurosaka <sho>
* Both cmew and smew in Haskell works well finally!
Shuichi KITAGUCHI <kit>
* Fixing info/Makefile.
Yasuhiro KIMURA <yasu>
* Guarding mew-addrbook-clean-up.
Hideyuki SHIRAI <shirai>
* A bug fix of mew-mime-content-type.
Yu-ji Hosokawa <yu-ji>
* Setting split-width-threshold to nil in mew-summary-reply.
* "b" in Summary saves the buffer of Message mode to a file.
* header-only now can work for M-x mew.
* Bold of font can be specified on Emacs 23.
* Deleting " " from global-mode-string.
Christophe TROESTLER <Christophe.Troestler>
* Correcting the -P option of stunnel3.
Kendall Shaw <kshaw>
* Define mew-sumsym-encode-folder and mew-sumsym-decode-folder.
* set-buffer -> with-current-buffer.
* Making mew-mime-image() safer.
Hideyuki SHIRAI <shirai>

(ryoon)