CMS-3488 Introduce UI Framework for responsive layout

Updated return value types for some functions.
Updated less media queries.
Merge pull request #747 from enonic/CMS-3488

CMS-3488 Introduce UI Framework for responsive layout
CMS-3559 Cleanup JaxRs code for OSGi.
CMS-3559 Cleanup JaxRs code for OSGi.
Merge branch 'master' into osgi