Merge pull request #74 from urosj/v4

Added /meta/revision-info API endpoint
Implement the charm-related API.

Also move MgoTestPackage suite registration out from api_test to its
own package_test.go.
Fix typo in comment.
Merge pull request #75 from frankban/charm-related

Implement the charm-related API.

Also move MgoTestPackage suite registration out from api_test to its
own package_test.go.
Implement the expand-id API.
Use bson.D where possible.
Use the router helper to write JSON data in the response.
Rename resolveURLError to noMatchingURLError.
Add more ExpandIdTests.
Merge pull request #76 from frankban/api-expand-id

Implement the expand-id API.
implement meta/revision-info
Implement the bundles-containing API endpoint.
Simplify the bundles-containing base query. Also return a bad request if flags are invalid.
Add a bundles-containing test with partial charm URLs.
Refactor the bundles-including endpoint include error test.
Implement a more direct way to filter the entities in the bundles-containing API endpoint.
Use baseurl to search and sort numeric

Use baseurl and remove entries which have different series.
Use numeric sort.
Add bulk api tests for the charm-related and bundles-containing endpoints.
add the revision-info to metaEndpoints

So that it gets tested with all the rest of the meta endpoint machinery.
Document comment the backward Less impl