refactorings.
Merge pull request #286 from est77/master

small linux fixes
on Windows, the appleseed Python module must have the .pyd extension.
Merge branch 'master' of github.com:jupiter-jazz/appleseed
minor tweaks.
minor tweaks.
rendermanager.py 2.2: make sure the destination directory exists before uploading a project dependency.
fixed regression introduced in 11e0ba1bde3a55e849e6f5be48aae4bbb85b0569 ("improved handling of assets when writing project files to disk").

also improved the asset handling code.
Python API improvements.

- added support for shallow and deep copy of appleseed.Tile and appleseed.Image objects.
- don't prefix color space and pixel format enumeration members with the enumeration name.
rendermanager.py 2.3: tweaked some log messages.
minor code cleanups.
tweaked the Python sample app to match the C++ sample app more closely.
fixed logger and other small python improvements
small changes to sample.py
Removed commented code
added .gitignore file.
sample.py improvements
fixed sample.py errors
Fixed PR comments
Merge pull request #287 from est77/py_improvements

fixed python logging and other small python improvements