Replace errant use of 'throw' with 'raise'

In Ruby, throw/catch is not related to exceptions, and without an catch clause somewhere up the stack, this will fail with "uncaught throw".

Replace it with a plain "raise" which will re-raise the current exception.
Release 2.0.0b7
opcache 7.0.2 update PHP 5.4/5.5
APCu v4.0.1
Add extension YAC (Yet Another Cache, developed by Xinchen Hui - laruence)
Fixed composer requirements for PHP55