Improve performance of truncation strategy
Improve performance of truncation strategy

Store schema reflection results statically. This reduces the number of
reflection queries we run to one per table. Previously a reflection
query would run per test / per fixture.

ADmad/cakephp,cakephp/cakephp,ADmad/cakephp,CakeDC/cakephp,ndm2/cakephp,ndm2/cakephp,cakephp/cakephp,CakeDC/cakephp,CakeDC/cakephp,cakephp/cakephp,CakeDC/cakephp,ADmad/cakephp,ADmad/cakephp,ndm2/cakephp,ndm2/cakephp,cakephp/cakephp