Fix tests
Fix #1791
Test case
Modify phalcon_get_global()

  * Do not use PHALCON_INIT_VAR() in phalcon_get_global()
  * Modify the signature of phalcon_get_global()
  * Optimize the code taking advantage of the new phalcon_get_global()
Update test case for #1401

See https://github.com/phalcon/cphalcon/issues/1790#issuecomment-32124801
Merge pull request #1792 from sjinks/tests

Fix tests