Global constants groupped in abstracts

[Aleksandr Kuzmenko]

Copied from #12 (comment)

@:phpGlobal
@:phpConstants("\\SOAP_SSL_METHOD_")
@:enum extern abstract SoapSslMethod(Int) {
  var TLS;
  var SSLv2;
  var SSLv3;
  var SSLv23;
}

Magic constants:

@:phpGlobal
@:phpConstants
extern class MagicConstant {
  @:native("__FUNCTION__")
  static var FUNCTION:String;
 ...
}

[Aleksandr Kuzmenko]

Having all native global consts in one extern class is pretty convenient since after checking php manual user don't have to search for a proper class with required constants, but always knows where they are