JBIDE-15152 jQuery Mobile palette contains mix of jQuery Mobile and HTML5 items

HTML entries are moved from jQuery Mobile to new category HTML
JBIDE-17003 Exception while using DnD from jqm palette into source

Added covertion document offset to visual one
JBIDE-17060 IncludeModel class has an error in logic

Error in algorithm is fixed.
Updated Execution Environment to JavaSE-1.7