SearchContext: Ensure occurrences_count is updated in an edge case
SearchContext: Ensure occurrences_count is updated in an edge case

When at_word_boundaries is set in the SearchSettings and an insertion
occurs on a word boundary, the affected occurrence needs to be
re-scanned. This commit changes remove_occurrences_in_range to
properly adjust the given boundaries to accomplish this.

https://bugzilla.gnome.org/show_bug.cgi?id=767978

GNOME/gtksourceview,uajain/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,uajain/gtksourceview,GNOME/gtksourceview,uajain/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,uajain/gtksourceview,GNOME/gtksourceview,uajain/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,uajain/gtksourceview,GNOME/gtksourceview,uajain/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,GNOME/gtksourceview,uajain/gtksourceview,uajain/gtksourceview,uajain/gtksourceview