go easy on saucelabs

 - ci tests should only run for master branch and pull requests
 - test of compiling all bundles work
 - publish docs only from master branch
Merge pull request #252 from plone/garbas-go-easy-on-saucelabs

go easy on saucelabs
backup structure updates
add tree selector to related items
refactor some of queryhelper
be able to use tus with dropzone
add drag drop pattern back
fix relateditems tests
fix to work with latest backbone
oops, debugger
fix various bs3 and backbone upgrade issues
fix related items with tree selector again
merge
more bs3 fixes