First pass at the LESS conversion

Still missing Blackberry10
Removing what are now build artefacts
Adding build artefacts to .gitignore
Added Blackberry10 .less file

...but it's just straight css for now
Add blackberry10 to less config in Grunt
Make custom brand / white label stuff work with less
Change some rogue "orange" colours to @highlightColor
Merge branch 'master' of https://github.com/SpiderOak/SpiderOakMobileClient into issue-467-convert-css-to-less
Needs an empty brand.less to include

Also a small bug fix for android passcode screens
Merge pull request #481 from SpiderOak/issue-467-convert-css-to-less

Issue #467 convert css to less