More permanent zvals
Do not indirectly modify properties with refcount > 1; use MAKE_STD_ZVAL instead of ALLOC_INIT_ZVAL where appropriate
Implement #1320, #907
Merge pull request #1321 from sjinks/perm-zvals

Use preallocated permanent zvals instead of null, true, false, 0 and 1
Merge pull request #1322 from sjinks/issue-1320

View::isDisabled(), View::getRenderLevel(), View::getDisabledLevels()