Creates more granular exceptions

This allows more fine control over which exceptions you can catch
with (hopefully) less string introspection. These exceptions have both
faultCode and faultString from the XML-RPC faults..

The Exception hierarchy is as follows:
* SoftLayerError
** SoftLayerAPIError
*** ParseError
*** ServerError
*** ApplicationError
*** RemoteSystemError
*** TransportError

These exceptions are thrown in accordance to XML-RPC spec.
 http://xmlrpc-epi.sourceforge.net/specs/rfc.fault_codes.php
Creates more granular exceptions v2

The Exception hierarchy is as follows:
* SoftLayerError
  * SoftLayerAPIError
    * ParseError
      * NotWellFormed
      * UnsupportedEncoding
      * InvalidCharacter
    * ServerError
      * SpecViolation
      * MethodNotFound
      * InvalidMethodParameters
      * InternalError
    * ApplicationError
    * RemoteSystemError
    * TransportError

Reference for standard xmlrpc fault codes: http://xmlrpc-epi.sourceforge.net/specs/rfc.fault_codes.php
Merge pull request #17 from sudorandom/exceptions

More granular exceptions