LP#1701001: carve out a reusable patron search service

LP#1701001: carve out a reusable patron search service

This patch moves the patron search service and the base
patron search controller into a separate, reusable
file.  The core patron search service is available for
injection as patronSvc from the new egPatronSearchMod, while
BasePatronSearchCtrl now exists as a base controller for the
patron search form that can be extended as needed by doing
something like this:

module.controller('DerivedPatronSearchCtrl', [
             '$scope', '$controller',
    function ($scope, $controller) {
    // Initialize the super class and extend it.
    angular.extend(this, $controller('BasePatronSearchCtrl', {$scope: $scope}));
...

Signed-off-by: Galen Charlton <gmc@equinoxinitiative.org>
Signed-off-by: Chris Sharp <csharp@georgialibraries.org>