Travis: Update URL for build status image.
Base: upgrade navbar.
main.css: Remove old css.
base.html: Remove brotatos' credit.
Use font awesome.
index.html: Fix label.
Add padding to body in order to prevent the navbar from overlapping.
Fix front page columns.

Adjust container width to 800px.
Adjust subtitles of projects.

Make them bigger and bold them.

This is merely for clarity.
Projects: row-fluid -> row.

Bootstrap 3 no longer uses "row-fluid" to denote a
responsive grid.
Fix projects page.

Update descriptions as well.
Fix registration form.
Fix login form.
register.html: Add spacing between captcha and other fields.
Login: Add spacing between button and link to register.
Adjust front page columns.

Add both large and medium sizes explicitly.
Adjust front page columns.

Add both large and medium sizes explicitly.