Build with WebKitGTK 2.2.0: Closes #7023
Build with WebKitGTK 2.2.0: Closes #7023

Unfortunately, CMake doesn't allow us to exclude WebKitGTK 2.1.1
to 2.1.90.0, which are the versions that don't have the symbols
we need to build cleanly.  We'll have to assume that anyone building
with an installed WebKitGTK package is using a stable release.

mjog/geary,martinra/geary,glebihan/geary,aatishnn/geary,robol/geary,mjog/geary,AtticHacker/geary,AtticHacker/geary,abn/geary,rschroll/geary,aatishnn/geary,mpdeimos/geary,mjog/geary,geekvigilante/geary,aatishnn/geary,rschroll/geary,AtticHacker/geary,emersion/geary,kpiwko/geary,jimbonator/geary,emersion/geary,emersion/geary,jimbonator/geary,martinra/geary,glebihan/geary,jimbonator/geary,githubnemo/geary,glebihan/geary,robol/geary,robol/geary,tshikaboom/geary,githubnemo/geary,tshikaboom/geary,martinra/geary,MohamedIM/geary-unofficial,githubnemo/geary,tshikaboom/geary