Fixes #58 - Adds About SpiderOak to menusheet.

Still needs to be available via a link on the login screen...
Refactored to allow for display from Login as well
Better CSS (no inline, etc)
Form names, tab indexes, etc
Merge pull request #161 from SpiderOak/about-spideroak

About SpiderOak screens

Fixes #58
Merge pull request #165 from SpiderOak/issue-164-tabindex

Form names, tab indexes, etc

Fixes #164
Merge branch 'master' into issue-151-alternate-server