internal/v4: fix search error handling
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.
Merge branch 'v4' of https://github.com/juju/charmstore into v4