JBIDE-16687 provide access to palette entries via content assist

Proposals filtering is skipped for the ones that come from Palette
JBIDE-17080 Clipboard operations doesn't work in Properties editor

Added missing functionality to DialogCellEditorEx
JBIDE-17165 jQuery Mobile Palette 1.3 still have HTML 5 items

Do not save Mobile palette which is read-only with
editable JSF palette. When saved it keeps items that
might be removed in new versions of JBoss Tools.
JBIDE-17148 api enhancement for url transport utility class

JBIDE-17148 - method should be private
JBIDE-17148 - fixes as per fred's suggestions
JBIDE-17168 Test Failure on Windows: PropertiesLoaderTest
JBIDE-17175 org.jboss.tools.jst.web.kb.test failure on Windows

Comment added to Libs.getLibrary(String) explaining that path should
use OS provided separator.
[no jira] Tiny change to stacks to split logic into new protected method. Adds signature protected Stacks getStacksFromFile(File f) throws IOException
JBIDE-17198 - add support for extracting tar and tar.gz files

Moved tar content to .xpl package
JBIDE-17148 and JBIDE-17179 - outdated test case updated
JBIDE-17215 - better handling of tar.gz extracting