Merge remote-tracking branch 'refs/remotes/origin/dev'
Hot Fixes
Update Twitter Bootstrap to 2.3.2
Create pl.lang.php

Localization: Polish(pl) translations added.
Create pl.lang.php
Create pl.lang.php
Create pl.lang.php
Create pl.lang.php
Create pl.lang.php
Create pl.lang.php
Create pl.lang.php
Create pl.lang.php
Create pl.lang.php
Create pl.lang.php
Create pl.lang.php
Create pl.lang.php
Create pl.lang.php
Create pl.lang.php
Update install.php

Localization: Polish(pl) translations added.
Fix Number.php: Undefined offset