JBIDE-17258 BrowserSim: use javaFx web engine for 64bit Windows

implemented, modified preferences page
JBIDE-17234 suggested improvements to dialogs to mention JDK7/8 instead of JRE/JDK 6 + JDK 7

Conflicts:
	plugins/org.jboss.tools.vpe.browsersim/src/org/jboss/tools/vpe/browsersim/ui/messages.properties
JBIDE-17243 Fix naming issues in Browsersim

modified error message names
removed java6 availability + cleanup
JBIDE-17224 Typo in BrowserSim WebKitGTK error message: is > has
JBIDE-17244 BrowserSim: Make able to use javaFx web engine on Linux if WebKit is not installed

implemented
error messages modification