Refactoring. Adding copyrights info and NON-NLS
JBIDE-18748: Remove ref to macosx x86 feature

macosx/cocoa/x86 isn't supported any more. Remove reference
to the platform-specific feature.
JBIDE-17818 Visual Editor: Need to handle external html / htm files

implemented
JBIDE-17818 Need to handle external html / htm files

bug when external file is opened with wtp editor fixed
error message is shown when Editor has no dom model support