complete rewrite

originally i thought this would be some simple alterations to the
existing ‘official’ wrapper. as i got more and more into it turned into
a complete rewrite. substitued class `apiRequestor` for generic Curl
class (can be used with other things, like maybe stripe or fb or
twitter).  got rid of all the `objects` because they were nothing more
than wrappers for arrays. easier to work with simple arrays IMHO.
custom error exception didn’t really add much so nixed it for built in
php exception. this style fits in much nicer with FWs like CI that
‘load’ libraries. also could instantiate a singleton. I like that
better than a ton of static methods.  I know there are bugs in here,
but wanted to get something down for now, and to possibly show
Postmaster team.