Magic Search filtering should provide default help content

[Cindy Lu]

As suggested by Travis here: https://review.openstack.org/#/c/217437/3/openstack_dashboard/static/app/core/images/table/images-table.controller.js

Instead of defining

ctrl.sourceFilterStrings = {
      cancel: gettext('Cancel'),
      prompt: gettext('Click here for filters.'),
      remove: gettext('Remove'),
      text: gettext('In current results')
}

everywhere, we can just make it a default in hzMagicSearchBar directive. If user doesn't pass in any filterStrings, we use the default instead.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/222710

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/222710
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=bb60aa4a33952f1d9bdea5c6a0646e9210952f48
Submitter: Jenkins
Branch: master

commit bb60aa4a33952f1d9bdea5c6a0646e9210952f48
Author: Cindy Lu <email address hidden>
Date: Thu Sep 10 01:24:06 2015 -0700

    Angular Magic Search defaults for filterStrings

    Rather that repeatedly defining the filter help text every time
    Magic Search is defined, we can make filterStrings optional.
    If it's not provided, we can use the defaults.

    Based off TravT's suggestion in images-table.controller.js here:
    https://review.openstack.org/#/c/217437/2/

    To test, rebase one of the Magic Search implementations on this patch.
    (e.g https://review.openstack.org/#/c/217437/) and remove filterStrings:

       <hz-magic-search-bar
         filter-facets="filterFacets">
       </hz-magic-search-bar>

    Change-Id: I9968c95da85063cbff81bc1ed4b15679dfaf58b7
    Closes-Bug: #1494532