fix(directives): Check for href twice in NgAAttrDirective
feat(Http): transformRequest, transformResponse
feat(http): AngularJS-style caching
fix(source_metadata_extractor): added support for ! attr map spec
feat(http): Setter for default headers
feat(ng-template): initial implementation

Closes #137
feat(ng-unless): new ng-unless directive

Closes #126
feat(Http): Pending requests
feat(filter): added basic filter implementation

Closes #151
Closes #144
Closes #147
feat(filter:json): add json filter

Closes #142
chore(directive): remove ng-controller

Closes #122
feat(Http): docs for the Http service.
chore(doc): correct typo
chore(directive): remove mg-controller from demos

Closes #122
chore(directive): merge all directives into single library
docs(Http): HttpBackend, HttpResponse, defaults.