metapost: comment regarding hole rendering
dox: documentation update for DiaObject member functions
cleanup: remove DiaObject::flags, add remove DiaObjectType::flags

The only object flag is a type property (parenting is object type specific).
There is no way to change it after construction and there must not be. This
reduces the size of DiaObject to 96 (32 bit OS) and just needs one
indirection per object_flags_set() call.
Also remove unused DIA_OBJECT_GRABS_CHILD_INPUT - another leftover from
the unfinished "new group" stuff.

tests>test-sizeof

DiaObject: 96
Connection: 224
Element: 392
UMLClass: 952
Handle: 32
ConnectionPoint: 32
pat-variations.svg: more paths with holes
Bug 680688 - disable most top menu items when there is no display

there was almost everything needed with display_actions, just some common_entries
not to be included for the integrated UI case, otherwise we could not load a
diagram or quit anymore.
image: remember mime-type from pixbuf loading to use it when saving

more efficient storage when working with embedded jpeg, for images in dia
native files as well as with SVG. Also optimize away a string copy of the
base64 encoding.
image: fix 'Standard - Image' set_props() for pixbuf changes

 - switch on inline data => make inline: set pixbuf, keep filename
 - switch off inline data => save pixbuf to filename, if new filename
 - set a new, non empty filename => load the file
 - set an empty filename => make inline
 - set a new, non NULL pixbuf => use as image, inline

Also provide a test file and an updated uninline_data.py script.
NEWS: mention render improvements and gradients
text: improve cursor positioning via mouse

the click had to be completely after the glyph, now the right half
of the glyph is enough
path: make handle behavior equivalent to other objects

Shear and Rotate are now available via context menu.

move_handle() is supposed to be just moving that and related handles (e.g.
when N is moved NE and NW will move too). But 'opposite' handles are not
to be moved at all. So our transformation is invariant to the opposite
point of the path, not the object position.