FMSLogo Code

Add missing #include directives to fix build breaks when USE_PRECOMPILED_HEADER is not defined.

Remove a TODO to enable WX_PRECOMP.
This has been done, but with a different precompiler symbol.

Fix the "test" target, which broke when "logo", "www", and "extras" were moved into separate subversion projects.

Fix build breaks on Windows that were introduced in the previous revision (getting CLEARSCREEN to run on GNU/Linux).

Implement ibm_clear_screen using wxWidgets so that it works on GNU/Linux.
This makes CS and the Reset button work correctly on GNU/Linux.

Move checkwindow() to a platform-independent portion of the code, since it uses pure wxWidgets API.

Rewrite checkwindow() to be platform-independent (using wxWidgets instead of win32 API)

Work around a problem that appeared on GNU/Linux after upgrading from wxWidgets 2.8 to wxWidgets 3.0.
For some reason, wxINVERT does not work in GTK (the lines it draws are invisible)

Update CScreen to work better with wxWidgets 3.X for GTK
* Change the super class to a documented type of wxScrolled<>.
* Change deprecated calls to PrepareDC to DoPrepareDC.
* Use m_DeviceContext.SetBackground() to set the brush for Clear()

Increase the minimum screen size from 200x200 to 400x400.

After upgrading wxWidgets from 2.8 to 3.0, the GTK default size no longer worked as before and a window size of 200 was clearly to small, as the commander width follows the screen width and 200 pixels is not large for the history and the buttons.