LP#1656036 Webstaff dynamic page titles

LP#1656036 Webstaff dynamic page titles

Support page/tab titles applied by page controllers.  Each title is
composed of 2 optional components, a dynamic component and a context
component.

The dynamic component may be interpolated with real-time data (e.g. a
patron's name) and the context is generally a page or tab-level value
(e.g. Checkout).

For example:  "Smith, Jane - Checkout"

Apply a title within a controller like so:

egCore.strings.setPageTitle(
    egCore.strings.MY_DYNAMIC_TEMPLATE,
    egCore.strings.MY_CONTEXT_STRING,
    {foo : 'foo', bar : 'bar'}
);

If no values are set, the default template-level title is applied.

Signed-off-by: Bill Erickson <berickxx@gmail.com>