Update version number to 4.0.0-RC2
Update version number to 4.0.0-RC2

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