static/scriptengine: use Handle instead of Persistence

fixes #569

v2: make it compatible with older versions of v8
Fixed black lines showing on breadcrumbs due to expand taking extra space #213
version: note #213 fix in changelog
travis: set FORCE_BUNDLED_WXGTK=off

so travis will use the wxGTK deb packages again
travis: insert missing 'D'

my mistake, I am dumb