gitweb: Convert generated contents to utf8 in commitdiff_plain
gitweb: Convert generated contents to utf8 in commitdiff_plain

If the commit message, or commit author contains non-ascii, it must be
converted from Perl internal representation to utf-8, to follow what
got declared in HTTP header.  Use to_utf8() to do the conversion.

This necessarily replaces here-doc with "print" statements.

Signed-off-by: Yasushi SHOJI <afa9ca3be149447780c2f7b524d61ed3d3db63f9@atmark-techno.com>
Acked-by: İsmail Dönmez <e327c9fb8e9480674a8de694371211e799d7292d@pardus.org.tr>
Acked-by: Jakub Narebski <a6a1517a087f9f64a72f41a0de57ff01fbb0e412@gmail.com>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git