libview: Cycle through form fields with tab button

https://bugzilla.gnome.org/show_bug.cgi?id=503706
help: Remove EvOpenRecentAction symbols from the docs
Fix some make distcheck issues
backends: Do not generate appdata files from makefiles

Substitute the mime types from configure instead to avoid adding
generated files to POTFILE.in that is problematic.
libdocument: Add remove_annotation to DocumentAnnotations.

https://bugzilla.gnome.org/show_bug.cgi?id=649044
libview: add ev_view_remove_annotation

Hide annotation windows if necessary and unset selected
element before removing an annotation.

https://bugzilla.gnome.org/show_bug.cgi?id=649044
Add Delete Annotation option to the view popup

Based on this patch:
https://bug649044.bugzilla-attachments.gnome.org/attachment.cgi?id=275731
by Jose Aliste.
Adapted to the new menu.
libdocument: add ev_mapping_list_set_remove

Needed to remove annotations from a mapping list

https://bugzilla.gnome.org/show_bug.cgi?id=649044
pdf: Implement remove_annotation virtual func

https://bugzilla.gnome.org/show_bug.cgi?id=649044
Refreshing annotations' sidebar upon deletion

When an annotation is deleted, the sidebar needs to
be refreshed so that the annotation is removed from
the list

See item 3 in this comment:
https://bugzilla.gnome.org/show_bug.cgi?id=649044#c33
Saving annotations when the window is focused

When an annotation is edited and the user clicks
the top right 'x' to close evince's main window
while the annotation window itseld still has the
focus, the changes on the annotation are
acknowledged and the user is prompted to save
them.
Fixing annotation window colors

The annotation window now is all of one color and
no border.
Improving annotation window appearance

The title is now bold and there is extra margin
space around the textbox.
Also fixing minor typo.
Closing annotation window by clicking on icon

When the annotation window is opened, clicking on
the corresponding icon closes it.