Initial import from PHP git

Change-Id: Ic4d61e8f3f2e22ea8ffcf907ea56f454932fc25a
HHVM files

Change-Id: Ia69ba35cb8b0e5008546e2a141b1baaa7ee442b3
Downgrade to PHP 5.5 since PHP 7 is weird

Change-Id: I451f5734073d350e97ed2cfc9b648a64bbf5c237