view: adding text markup annotations

Implemented the creation of text markup
annotations in view.
view: saving annotation area in mapping

Once the button is released, the annotation area
is saved in the annotation mapping.
Adding sidebar icons to add annotations

Adding icons to add highlight, strike out,
squiggly and underline. Line and free text still
depend on updates of poppler.

Based on kcm's (Anuj Khare) patch.