html, etc

According to http://golang.org/pkg/net/http/#DetectContentType
"If the Header does not contain a Content-Type line, Write adds
a Content-Type set to the result of passing the initial 512 bytes
of written data to DetectContentType."

Signed-off-by: Dmitry Yu Okunev <dyokunev@ut.mephi.ru>

fix typo in centos init script

We should be *sourcing* `/etc/sysconfig/gogs`, not *executing* it, don't we?

Set Content-Type to text/plain for http status 401

This is because git command line shows the failure reason only if Content-Type is text/plain.

Fix "Plus" icon size in dashboard

fixed panic error on user login

Fix email contact and link

Allow to migrate through git:// protocol

- fix bug when add a repo to team, all other team members gets access as well

- code format for #1020

Exclude HTML tags from Markdown post-processing

Fixed minor gramatical error in the US install success msg

Apply ng to issue dashboard