Update to WebFragments 3.0.7 and WebResources 3.1.2

Having released new versions of WebFragments and WebResources that moved a bunch of dependencies to provided scope, move RefApp onto these.

Also tidy up some conflicting javax.servlet versions.

EDIT - I just bumped this to 3.1.2 (In 3.1.1 I'd moved the webresource api to provided. Moved it back to compile scope, so it's brought in automatically with the webresource core)