Adding anonymous account support

* Added anonymous flag to accounts table
* Added checkbox for anonymous flag in edit account page
* Updated user class to support new flag
* Updated statistics class to support anonymous and donations
* Updated all templates showing usernames to show anonymous instead
* Added new SQL `ALTER TABLE` file for upgrading the table

Fixes #419 once merged.
add check for non alpa/-/_ chars
Merge pull request #453 from typal/issue-452

add check for non alpa/-/_ chars
Merge pull request #454 from TheSerapher/issue-419

Adding anonymous account support
fucked up...
Merge pull request #455 from typal/issue-452

fucked up...
Fixing username regexp during registration

Fixes wrong regext of #453
nag for donations
extra js
Merge remote-tracking branch 'upstream/next' into next