Grammar and spelling

Improved grammar and corrected spelling.
Update lang.php
Type in oc-icon-paperclip class

Fixed type in oc-icon-paperclip class (from paper-clip to paperclip) which meant that the attachment link wasn't showing in backed.
Merge pull request #833 from mradamwood/patch-1

Typo in oc-icon-paperclip class
Merge pull request #832 from andreas-bergstrom/patch-1

Grammar and spelling