Added pagination to search queries

A new skip parameter can be added to search queries and the results
will start from that offset in the overall search results.
Merge pull request #192 from mhilton/search-pagination

Added pagination to search queries

A new start parameter can be added to search queries and the results
will start from that offset in the overall search results.
* removing oneiric as allowed series
* removing raring and quantal as well
internal/v4: fix search error handling
Merge pull request #195 from urosj/v4

Removing oneiric as allowed series.
Throwing out CharmConfig from indexing.
Merge pull request #194 from rogpeppe/082-fix-search-errors

internal/v4: fix search error handling

We use the new HandleJSON API which doesn't give a ResponseWriter
to use.
all: use bundle/wordpress-simple in tests
Merge pull request #197 from rogpeppe/084-use-wordpress-simple

all: use bundle/wordpress-simple in tests

Also update dependencies to use wordpress-simple bundle
from the updated charm.v4 package.
internal/charmstore: do not allow charms and bundles to have the same names
Merge pull request #198 from rogpeppe/083-disallow-same-bundle-charm-names

internal/charmstore: do not allow charms and bundles to have the same names

This enforces (with high probability) the flat name space we want for the future.
internal/charmstore: remove entity if ES insert fails
Merge branch 'v4' of https://github.com/juju/charmstore into v4
Merge pull request #196 from urosj/v4

Throwing out CharmConfig from indexing.
Merge pull request #199 from rogpeppe/085-fix-add-entity

internal/charmstore: remove entity if ES insert fails
charmstore: add CORS headers to all requests
Merge pull request #200 from rogpeppe/086-CORS

charmstore: add CORS headers to all requests

To QA this, we need to create a web page that contains some javascript
that makes an AJAX request to the charm store, and check that it
succeeds.
internal/storetesting: add YAMLEquals checker
Merge pull request #166 from rogpeppe/073-yaml-equals

internal/storetesting: add YAMLEquals checker

We want this for checking YAML output elsewhere.