Add bounding-rectangle property to EvAnnotation

This allows an EvAnnotation to know its location on the page.
Add EvQuadrilateral type required for text markup annotations.

EvQuadrilateral is a simple boxed type containing 4 EvPoints
that constitute the corners of a quadrilateral.
PDF markup annotations make use of this structure to define
an annotation's active area.
Add support for interactive areas in annotations.

Some annotation types do not have a rectangular shape
and require non-rectangular boundary checks to determine
if the user clicked on them.

A new method ev_annotation_is_location_in_area() is added
that determines whether a point location is actually
inside the annotation's interactive area.
Renaming annotation interface methods

text_markup_iface_init was renamed to
text_iface_init to avoid clashing with actual text
markups of future implementations. The attachment
method was also renamed to keep uniformity.
Add EvAnnotationTextMarkup class.

This base class should be used for all text markup
annotations like text highlighting, underlining, etc.
libdocument: Add freetext annotations
pdf: Add support for freetext annotations

Waiting for poppler patch.
Add support for POPPLER_ANNOT_HIGHLIGHT

https://bugzilla.gnome.org/show_bug.cgi?id=583377
Add support for POPPLER_ANNOT_STRIKE_OUT

https://bugzilla.gnome.org/show_bug.cgi?id=583377
Add lines annotations

Making EvPoint a boxed type to be used by the line
annotation and adding all necessary backend
machinery to support line annotations.

Modifications on gpoo's commit by giselle
(gisellemnr@src.gnome.org).
Adding squiggly and underline annotations

Implementing the back-end support for underline
and squiggly annotations.
Support for drawing annotations in libview

Added different modes for inserting annotations.
Those which need only one point are added
immediately when the user clicks on the view.
Those that need two points (line, text markups,
etc) enter in MODE_DRAW and the second point is
set as the mouse is moved and when the button is
released the mode goes back to MODE_NORMAL.

Based on gpoo's patch.
Only text annotation has a popup
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.