Clear bookmarks and index on journal deletion
Update page number when bookmark is moved to a different page
Implement saving/opening of bookmarks into the XOJ
Bookmark column headers clickable/sortable. Sorts by page number by
default.
Sorting of bookmarks within a page
Prevent bookmarks from being deleted from the canvas.
Default bookmark name + "Enter" key in GtkEntry accepts dialog
Editing of bookmark names
Toolbar item for creating bookmarks + creation of bookmarks relative to
current scroll location
Code cleanup
Merge branch 'bookmarks'

Conflicts:
	src/xo-callbacks.h
	src/xo-misc.c
Merge branch 'master' of github.com:andpol/xournal
Add graphic for bookmarks and make bookmarks excempt from undo/redo
Handle deleting pages/layers with bookmarks on them
Fix opening of XOJ files with bookmarks
Fix glade file breakage
Actually fix the Glade file...
Add forgotten bookmark pixmap
Include bookmarks in the thumbnails.
Fixed bugs with colors and made the color gradient more sensitive to motion