Mail subject charset

[Polfo]

This solves #110 in my setup.
I am not shure it works in all settings.
I use gmail web client and see the following headers through Show original

Subject: ...Gústa... - New Commit
Content-Type: text/html; charset=UTF-8

instead of

Subject: ...Gústa... - New Commit
Content-Type: text/html; charset=ISO-8859-1

maybe a universal solution requires a subject formated like this

=?UTF-8?B?R8O6c3Rh?=