libdocument: Add EvAnnotationTextMarkup GObject.

Add EvAnnotationTextMarkup GObject. This object is a wrapper
for PopplerAnnotTextMarkup GObject, which manages Highlight, Underline,
Squiggly and Strike Out PDF annotations.
pdf: Add support for Text Markup Annotations.

Add basic handling for Highlight, Underline, Squiggly and Strike Out Annotations.
This allows to see/edit the contents and basic properties of the Annotations.
libdocument: Replace PROP_ATTACHMENT_ATTACHMENT for PROP_MARKUP_POUP_IS_OPEN.

When checking whether a prop id belongs to the annot_markup interface, the checks
are done with (prop_id < PROP_ATTACHMENT_ATTACHMENT). We change these checks
to (prop_id <= PROP_MARKUP_POPUP_IS_OPEN) which are completely equivalent
as PROP_ATTACHMENT_ATTACHMENT = PROP_MARKUP_POPUP_IS_OPEN + 1, but
they provide better readibility of the code.
libview: Make ev_view_reload_page public

This is needed so evince can redraw a page after an annotation in that page is removed.
libdocument: Add remove_annotation to DocumentAnnotations.
shell: Add RemoveAnnot action to the view popup.
pdf: Implement remove_annotation virtual func.
Add INK and SQUARE
Add ANNOT_FREE_TEXT
Made annotations sidebars one-liner
pspdf backend (work in progress)