FMSLogo Code

Fix bug #338; SETACTIVEAREA now throw errors when given non-integer values.

This required a little refactoring of the argument and conversion logic to provide an "integer only" argument checker.

This revision also includes a regression test that SETACTIVEAREA persists the new settings to the configuration.

Add function comments to numberp()

Add a function to uninitialize the DLL subsystem. This cleans up memory which a Logo programmer may have forgotten. It also fixes an assert failure in the case when DLLFREE is not called.

Enable the procedures in term.cpp under WX_PURE.
This unblocks running the screen.lgo tests on GNU/Linux.

Use the same flags for CCommanderDialog, regardless of platform.
I don't remember why different platforms had different flags, but I
expect that I had misread some documentation that wxSYSTEM_MENU didn't
exist on UNIX.

Don't register an event handler for EVT_STC_CLIPBOARD_PASTE on
wxWidgets versions less than 3.1.0, where it is not defined. This
unblocks further development for Fedora Core, whose most recent
wxWidgets library is 3.0.2.

Remove a "bool Padding" in the Turtle struct that wasn't referenced by the code. I assume this was added so that an array of Turtle would be word-aligned for performance, but compilers do this anyway and having an explicit field for padding only risks making the structure larger than needed.

Replace comments that referred to the "OWL-based version of FMSLogo" with "MSWLogo" or simply remove them. This was done to remove confusion for anyone reading the code, since the OWL-based version of FMSLogo no longer exists.

Fix a bug number reference to use the new bug number after SourceForge made each project have its own number space.

Replace a call to "sprintf" with a call to "snprintf". The only reason snprintf wasn't used originally is because Borland's compiler didn't support it. Now that FMSLogo doesn't use OWL, it does not need to use Borland's compiler, so it can use snprintf.