Adapt login screen for more devices.

Always show only one column.
Center that column.
Smaller font size on the title so that it can fit on smaller devices.
Add css overrides for missing panel padding in bootstrap 3 RC2.
Remove comments in main.css.
Extract new game form to an external template.
Print error information and highlight erroneous inputs on when failing to add new games.
Persist input values between failed input attempts in the new game form.
Make the overview link in the top menu actually link to the overview page.
Include stake information once again in the game overview table.

Make the page readable on small devices by hiding certain columns that are not of interest when viewing the page on mobile devices.
Also added som utility classes to the css for aligning text left/center/right.
Adapt the new game form for smaller devices.