Updated Spanish translation
libview: Make caret cursor blink

Based on GtkEntry and GtkTextView implementation, the caret cursor
blinks when the view is active and caret navigation is enabled. It stops
blinking after a while if there's no user interaction. It uses
GtkSettings:gtk-cursor-blink-time and
GtkSettings:gtk-cursor-blink-timeout.

https://bugzilla.gnome.org/show_bug.cgi?id=702076
libview: Avoid to update the current page and scroll to the cursor position, if the caret cursor was not updated

Move the caret cursor only when requested by the user. Keep the page
where the caret cursor is in addition to the offset inside that page.

https://bugzilla.gnome.org/show_bug.cgi?id=702068
libview: Actually update the page when moving the care from a different page

I removed the line to set the current page after moving the caret cursor
by mistake. Add it back and change cursor_go_to_next/previous_page to
not update the page, but only update the cursor_page so that we have a
single place where the page is updated after caret cursor moves.
sidebar-thumbnails: Connect to job finished signal before scheduling the job

The bug fixes a race condition.

https://bugzilla.gnome.org/show_bug.cgi?id=701900
libview: Fix the damage area used to redraw the caret cursor

Move to a helper function the code to get the exact area where the caret
should be drawn and use it to draw the care cursor and to invalidate the
area when blinking.
libview: Don't update current_page to negative number

In continuous mode with dual page view, there is a chance
that the pages were outside of the scroll view.  When
opening a document in such circumstances, the current
page should not be updated to a negative number when
already has the first page as default.

This fixes a crash when searching with a negative
current page.

Fix https://bugzilla.gnome.org/show_bug.cgi?id=683172