JERSEY-2120: Update MVC documentation
JERSEY-2103: not optimal implementation of the FreemarkerViewProcessor

 - Major update of MVC documentation
 - resolving class marked as deprecated
 - refactored SPI (AbstractTemplateProcessor + test)
 - optimized Freemarker template processor
 - introduced caching property and ability to set custom template object factory
 - properties of supported templating engines moved to *Feature file instead of *Properties
 - Review of MVC documentation incorporated

Change-Id: I580d0c9aec1c7d38c15d4fa591706a6b831b52e3
Signed-off-by: Michal Gajdos <michal.gajdos@oracle.com>
Merge "JERSEY-2120: Update MVC documentation JERSEY-2103: not optimal implementation of the FreemarkerViewProcessor"