EvSidebarThumbnails: render thumbnails correctly for hi-dpi displays

Render thumbnails with resolution from gtk_widget_get_scale_factor() and
recreate them when the scale change. Make the thumbnail-rendering helper
functions create a hi-resolution surface when the widget has a scale
factor.

https://bugzilla.gnome.org/show_bug.cgi?id=723431
libview: Fix g_return condition in set_device_scale_on_surface()

Fail when device scale is not 1 if hidpi is not available, we were doing
the opposite.
Remove the  Next-Page and Previous-Page buttons from the toolbar.

Move the actions to the View menu.
Also move the Last Page and First Page to the View menu.

https://bugzilla.gnome.org/show_bug.cgi?id=732289
Remove unused ev_toolbar_create_button and ev_toolbar_create_button_group

https://bugzilla.gnome.org/show_bug.cgi?id=732289
"<Ctrl>Home/End" scroll to the start/end of the document

Before they scroll to the first/last page. This is now managed
by the view, instead of the window.

https://bugzilla.gnome.org/show_bug.cgi?id=724273
libview: Emit accessible focused-changed signals for form fields

https://bugzilla.gnome.org/show_bug.cgi?id=733662
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.
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.
Annotation default colors

Highlight: yellow
Strikeout and underline: black
Squiggly: red