Updated Page Builder to Version 1.5

* Increased size of widget dialog boxes.
* Updated incompatible plugins list.
* Updated to latest version of Chosen.
* Custom Home Page feature now uses standard pages.
* Improvements to preview handling.

git-svn-id: https://plugins.svn.wordpress.org/siteorigin-panels/trunk@943493 b8457f37-d9ea-0310-8a92-e5e31aec5664