Added initial PHP Halcyon client library file and structure.
Added initial PHP Halcyon client library file and structure.

DouglasAllen/halcyon,mtodd/halcyon,bsimpson/halcyon,DouglasAllen/halcyon,bsimpson/halcyon,bsimpson/halcyon,mtodd/halcyon,DouglasAllen/halcyon