WIP: Rewrote request/response handling to allow more flexible extension points

TODO: Update README

Added new configuration option fullResponse to allow returning full $http response from operations.  The new $http method also supports specifying resource configuration overrides to change settings on a per-request basis.

The new interceptor processing allows for intercepting both requests and responses synchronously or asynchronously at multiple phases in the process.

Deprecates: requestTransformers, responseInterceptors, afterResponseInterceptors have been replaced with a single interceptors chain.
Deprecates: beforeRequest - Use interceptBeforeRequestWrapping
Deprecates: beforeResponse - Use interceptResponse
Deprecates: afterResponse - Use interceptAfterResponse

Closes #87
Closes #91
Closes #64
Closes #58

BREAKING CHANGE: railsRootWrappingTransformer and railsRootWrappingInterceptor were replaced with railsRootWrapper that has wrap & unwrap methods to eliminate th eneed for using promises during resource construction.  Resource constructor no longer executes response interceptors.  If you need to customize the constructor you should look at using subclassing instead.  Removed methods processResponse, transformData, callInterceptors.