Fluid 5180: simplified lookup into message resolver

Simplified the process of looking up string values from the message resolver. This has been done by adding a new stringBundle grade that provides a lookup function that can be used through IoC ("{that}.stringBundle.stringName"). It also handles the case where arrays of strings are to be returned, by using a stringArrayIndex option in the component. 

http://issues.fluidproject.org/browse/FLUID-5180

Since the slidingPanel needed to be modified to make use of this new feature, took the time to modernize the code and address a few outstanding issues.

http://issues.fluidproject.org/browse/FLUID-5177
http://issues.fluidproject.org/browse/FLUID-5119
http://issues.fluidproject.org/browse/FLUID-5020
http://issues.fluidproject.org/browse/FLUID-4569
http://issues.fluidproject.org/browse/FLUID-4410