Initial port of wxPython demo from Classic to Phoenix.

Pulled and squashed from https://github.com/RobinD42/Phoenix/pull/7
Thanks Metallicow!

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/Phoenix/trunk@74199 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Ensure the CWD is the demo folder when running samples standalone

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/Phoenix/trunk@74200 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
- Use run.py when running standalone.
- Other minor tweaks

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/Phoenix/trunk@74201 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add MacCheckSpelling()

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/Phoenix/trunk@74202 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Only Freeze/Thaw if running on Windows

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/Phoenix/trunk@74203 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Generate demo/version.py in the build script.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/Phoenix/trunk@74204 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
- The keepReference hack is no longer needed for factory functions
- Add some missing DC methods
- minor fix in the GraphicsGradient demo

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/Phoenix/trunk@74205 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775