Removing Client module

- classes defined under Stormpath::Client have been relocated to Stormpath module

- removing "include Stormpath::Client" (it no longer exists)
Relocating TestResource to fix require-error
Removing Resource, DataStore, and Client modules

- classes defined under Resource module now defined under Stormpath module (the same goes for classes defined under DataStore and Client)

- Stormpath::DataStore::DataStore (class) now resides under Stormpath module

- Stormpath::Client::Client (class) now resides under Stormpath module

- Stormpath::Resource::Utils --> Stormpath::ResourceUtils (Resource module has been removed)

- Stormpath::Resource::Error --> Stormpath::ErrorResource (Resource module has been removed)
Updating rdoc to reflect new class structure
Updating specs to reflect new namespace
Merge pull request #14 from stormpath/enhancements/module_code_reorg-3

Enhancements/module code reorg 3