Responsive Curve2

This PR gives SMF 2.1 to handle some resolutions to display properly (aka Responsive). Admin side currently untouched and probably stay that way for now.

##### Tested with:
- Nokia Lumia 520
- Samsung Galaxy S3
- Samsung Galaxy Note2
- Samsung Galaxy S4
- Nexus7

Fixes #272
Fixes #347
Signed-off-by: Antes <antes@simplemachines.org>