finishing touches (+2 squashed commits)
Squashed commits:
[30a0d76] fixed most css build issues after switch to ui-library-agnostic enketo-core 2.x.x
[9fb4ae0] added bootstrap, switched to grunt-sass
upgraded enketo-core to major new version that does not have bootstrap dependency, closes #328
upgraded XSLT library with fix for autocomplete attribute
fixed aria-labelledby attributes on dialogs - they were not valid HTML
corrected link in README.md
reduced logging
Merge branch 'master' of https://github.com/enketo/enketo into production-auth