Revert "Removing DFP Api integration"

This reverts commit 8821c67d8094860ab7d8a7cb921cebb609e8c691.
Downgrade DFP Client Library
First pass at preview server
Merge branch 'master' of github.com:guardian/frontend into content-preview
Merge branch 'master' into kc-tc-test

Conflicts:
	common/app/dfp/DfpAgent.scala
Merge branch 'master' of github.com:guardian/frontend into content-preview
Keep All Dependencies of DFP Client

Should work when we deploy multiple jars
instead of a single fat jar.
Only Fetch All Keyword Targeting Values Once

Instead of fetching entire list for every line item.
Merge branch 'kc-tc-test' of github.com:guardian/frontend into kc-tc-test

Conflicts:
	project/Frontend.scala
Stubbed out commenter activity endpoint.
Remove tag routes from facia
Delete all unused code from facia
Change tag combiner router in applications to reflect what was in facia
Update applications code to what was in facia
Remove the FaciaController usage of IndexController in place of an
X-Accel-Redirect to /applications/path
Merge branch 'master' into kc-tc-test
wip
Merge branch 'master' into move-back-applications

Conflicts:
	facia/app/views/fragments/indexBody.scala.html
Build Target Model
Tidy up content class
Add has showcase boolean field