Remove some outstanding calls to titania_url's build/unbuild methods.
Add missing U_ALL_SUPPORT template variable.
Bump 3.1 branch to gold.
Merge branch 'ascraeus' into develop

* ascraeus:
  Bump 3.1 branch to gold.
  Add missing U_ALL_SUPPORT template variable.
  Remove some outstanding calls to titania_url's build/unbuild methods.
Configure extension releases forum.