Fix - Can't work manager except utf8

#257 Manager doesn’t work with ISO-8859-1 based MODx installations any
longer
Support for encoding windows-1251 in the emails
Patch https://github.com/modxcms/evolution/commit/98e68cbab53dd6523bb65243a9a654263cd8423d
tabs =)
Merge pull request #330 from olegpro/charset_issue

Support for windows-1251 encoding in emails
Update modxmailer.class.inc.php

Small fix
Merge pull request #331 from Segr/bugfix

Bugfix for commit modxcms@98e68cb
Merge commit '645503e407ac75064781f7ff39b7113b382d9ff3' into bugfix
Merge branch 'bugfix' of https://github.com/modxcms/evolution into bugfix