Layout v1.4.3 - Maintenance Release

Fix reported bugs:

• Change use of reserved word "native" in state-management module
• Fix logic bug that caused layout masks to not be removed correctly
• Replace depricated $.support.boxSizing with internal test, exposed as $.layout.browser.boxSizing
• Misc. minor refactoring of scripts and one demo page

Also added minified versions of Layout Javscript files, using Google Closure.

Layout State-Management Update

No changes to the core Layout widget are included in this release, but the Layout State-Management plugin was updated. This includes updating the combined layout_and_plugins file. Two statement-management demos were also added.