cleanup: remove declarations from objects/
Fix laod_accels() and print-action finding for integrated UI

The former was broken for quite a while, the latter a regression added recently.
[gradient] No editor, but pattern presets

Implement DiaPatternSelector as a dedicated property editor which
currently only facilitates gradient presets from background and
foreground colors. One day it might learn to actually preview the
patterns or even edit colors tops and other parameters.
dox: fix typos and add some more documentation
Fix line endings
Bug 727872 - Refer to dia-list@gnome.org for discussion
[warningectomy] dynamic cast to GtkAdjustment*

With gtk-3.0 the return value is changed to GtkAdjustment* so this will
become a no-op. With gtk-2-2x remove the warning.
samples: bezier-approx.dia

useful to debug rendering, especially Bézier variations
wmf: bézier rendering was using the wrong offset
svg: implement DiaSvgRenderer::is_capable_to()

Everything but RENDER_ALPHA remains disabled to accommodate for the
ShapeRenderer needs. The SvgRenderer used for SVG export adds all
the capabilities.
Improved fallback for DiaRenderer::*_rounded_rect()

If the derived renderer implements it's own draw_bezier or fill_bezier method
the fallback for rounded_rect is using that instead of arc/line/rect steps.
std-props: use text_set_*() for property setting with tow offsets
import: Implement DiaImportRenderer as a helper for further file import

This is finally the implementation of an old idea of mine: for file formats
which are basically serialized drawing commands it should be relative
straightforward to create the Dia objects via DiaRenderer interface. The WPG
format is in this category and the respective plug-in had initial code for
this idea for years. The following wpg-import.c is proof of concept and used
to debug this code.
Standard - Image: handle pixbuf change

the "not implemented" warning was triggered by image creation via
DiaImportRenderer::draw_image.c()
wpg: overhaul of WPG export and implementation of import

Export had some things wrong for years, like:
 - images were flipped upside down
 - WPG Polycurve was not used due to some misunderstanding with the
   specification http://www.fileformat.info/format/wpg/egff.htm
 - object positioning was slightly wrong

Import was only test code compiled on Windows, now:
 - split test code to it's own file and make it a full WPG importer
 - can read in again everything Dia writes with the exporter
 - some type information still lost due limitations in WPG (e.g. font
   handling, image bit depth and alpha) as well as limitations with
   Dia (e.g. no filled arc object yet)

Exported files (render-test.dia, std-props-test.dia bezier-approx.dia)
were tested for conformance with WordPerfect 5.1 (DOS) and "My ViewPad"
4.1.122 (Windows 7/32).
Also some test were performed with Inkscape 0.48.1 but Inkscape's WPG
import has issues with positioning, filling, line style, text, arcs and
poly curves at least.
drs: overhaul format, export and render import

 - the render script language is simplified by stripping 'draw-' and
   'fill-' prefix to rendering command. The draw or fill must be used is
   deduced from the attributes 'fill' and/or 'stroke'
 - import from rendering command finally got implemented as a fallback for
   unknown object types
 - no more G_GNUC_UNUSED necessary, everything is used and debugged now;)

To test the new rendering import either some object plug-ins used for creating
a file need to be disabled or the object type needs in the exported file need
to be renamed.
drs: alpha support, simplified