FMSLogo Code

Fix a bug that only manifested itself when using the libc on GNU/Linux.
The bug is that do_execution gave wcscpy overlapping regions, which
has implementation defined behavior. On GNU/Linux, this resulted in
weird behavior when the text typed into the commander has backslashes.

The fix to not use wcscpy, but instead perform that logic in do_execution.
The code was also reworked not to modify the given string, but to perform
the backslashing on a separate buffer. It uses make_strnode_no_copy so that
this change didn't result in an extra copy, only where the copy happens.

Add a regression test for defining and calling a procedure that has special characters in its name.

Fix a problem on GNU/Linux where the turtle commands didn't draw when zoomed.

Set the size of the wxHyperlinkCtrl to match the size of the link text.
This ensures that the About box looks the same on GNU/Linux as it does on Windows.

Fix a typo: "the link Help->About" -> "the links on Help->About".

Add a link to UCBLogo's homepage to the About box.
Now that it's easy to add links, why not?

Fix the GPL references in the About box.
The correct name is "GNU General Public License".
The "G" stands for "General" not "GNU".

Change the multimedia logic second the "About box" to be a panel.
This doesn't matter much on Windows, but gives a consistent appearance on GNU/Linux because GTK+ doesn't support wxBORDER_SUNKEN for wxStaticText.

Make the link to the Logo forum in the About box clickable.
This also changes the link from the Yahoo group to the FMSLogo discussion forum.
The Yahoo group closed and, according to Daniel Ajoy, the replacement Google group is not active.
This also removes the reference to the Usenet group, since Usenet is mostly defunct and participation in it is beyond most FMSLogo users.
For the Spanish/Portuguese URLs, I changed them from HTTP to HTTPS.

Put the "special thanks" and "GPL" into their own About Box panel.
This doesn't make much different on Windows, but gives a consistent look on GNU/Linux systems, which don't support SUNKEN_BORDER for wxStaticText.