Also changes the avatar from a jpeg to a png, to allow for
transparent background. The indexed png is also smaller in size.
Note that at the moment the default avatar is only used when
the user requested a custom avatar and the custom avatar file
is not found (should never happen).
In the future the default avatar could be used as a default
return when by-mail avatar lookups fail too (both gravatar
and libravatar support passing a default)
Always send user to settings screen to change avatar.
Drops "change_custom_avatar" localized message, keeps "change_avatar"
for the generic one.
NOTE: only changes the en-US locale, as per
https://github.com/gogits/gogs/wiki/Contributing-Code#those-we-do-not-accept
NOTE: requires rebuild of bindata.go to fully see effects
* Do not write HTML in text/plain mail part
Fixes#2928
* Pass text/plain first, text/html second
* Do not send plain/text email if html2text failed (untested)
Sandro Santilliand无闻