Added support for custom headers for requests in the PHP client. Also refactored much of the way headers are handled in general and defaulted to.
Added support for custom headers for requests in the PHP client. Also refactored much of the way headers are handled in general and defaulted to.

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