[GSoC] Zoner Draw import, project results

libzmf currently supports importing of Zoner Draw 4-5 documents and BMI
images (bitmap format used in Zoner Draw).

Supported features:
- layers, pages
- curves (lines, bezier curves, curve combinations)
- rectangles
- ellipses
- arcs
- polygons, stars
- barcodes
- object groups and combinations
- rotation, mirroring
- text. Font, size, alignment, bold/italic, line spacing.
- tables
- images
- fill: color, gradient (only linear and radial), image
- pen: color, width, line caps and corners, arrows, dashes
- transparency
- shadows

Missing features:
- Arc mirroring and rotation not fully implemented.
- Blend. Decided to skip this for now to finish more important features.
- Rectangle round corners.
- Table cell text vertical alignment. Not reverse engineered yet.
- There are some issues with table cell borders. Possibly a bug in
LibreOffice or ODF generator.
- Advanced text features such as outline fill color, custom baseline curve
and mirroring. Not supported in librevenge/ODF.
- Image fit and crop placement. Not supported in librevenge/ODF for images
but probably can be implement using image fill.
- Pen calligraphy properties: stretch, angle. Not supported in
librevenge/ODF.
- Complex dash patterns (more than 2 different dashes). Not supported in
librevenge/ODF.
- Arrow position is wrong for half of the arrows. Possibly a bug in
LibreOffice or ODF generator.
- Conical, rectangular, cross-shaped gradients. Not supported in
librevenge/ODF.
- Shadow blur. Not supported in librevenge/ODF.
- Skewing/deforming ("Perspective"). Too difficult to implement.

Code:

libzmf
https://gerrit.libreoffice.org/gitweb?p=libzmf.git&a=search&h=HEAD&st=author&s=alex

libzmf-test
https://gerrit.libreoffice.org/gitweb?p=libzmf-test.git&a=search&h=HEAD&st=author&s=alex

libzmf integration to LibreOffice
https://gerrit.libreoffice.org/gitweb?p=core.git;a=commit;h=aaed6fe55a67ee3e92bedf9eed2e2f7c044be19d

OleToy, reverse engineering of zmf4
https://github.com/renyxa/re-lab/commits/master?author=alex.pantec@gmail.com