Hide "Unknown extension point: 'org.eclipse.angularjs.core.angularNatureAdapters'" Error which is not relevant for the project

Signed-off-by: vrubezhny <vrubezhny@exadel.com>
Updated parent pom to Beta3
JBIDE-17472 Unable to edit preview text in CSS Preview view.

Updated "Double click to edit preview" to "This is a Preview Text"
JBIDE-17169 HTML5 Palette templates should be available for content assist by key words

Added keywords to Mobile Palette items. Modified xml tag completion
proposal computer to apply keyword when cursor is within a text node
to proposals and set high relevance to those having the keyword.
Tests are added.
JBIDE-17487 Improve layout of Ajax and Enhance checkboxes in jQuery Properties

Ajax and Enhance checkboxes are put to one line in the default form.
JBIDE-17408 use tern 0.2.0.201405210810 instead of 0.2.0 (with version range)