Remove depracated extended source stuff from configure.
Revert "Remove depracated extended source stuff from configure."

This reverts commit 9a85c0d7638f524e1f31e7853bc54aa34c63d41f.
Merge branch 'master' into Fluidity-intel-build
Merge branch 'Fluidity-intel-build' of https://github.com/FluidityProject/fluidity into Fluidity-intel-build
Change tolerance so that tests passes with an optimized build.