FMSLogo Code

Fix a bug where the first three characters were removed when writing to the clipboard.
Also add test cases for writing unicode content to clipboard, which required being able to read unicode content from the clipboard via DLLCALL.

Fix a file handle leak when the clipboard file is closed.
This open handle prevented the "temp" clipboard file from being deleted.
This was a regression introduced by the Unicode refactoring and had never been publically released.

Fix Bug #530; Fix a crash when using OPENUPDATE "clipboard
This was caused by using an unitialized FILE* when the filename was "clipboard" and anything other than OPENREAD (text mode) or OPENWRITE (text mode) was run.

Note that Bug #63 was fixed in FMSLogo 7.7.0 and add a regression test.

Remove the last call to ShowMessageAndStop()
This was buried in DIBToBitmap, which wasn't quite right, because on caller was the message pump.
The caller can check the return value if they want to either throw an error or show a dialog box.
None of the callers do because FMSLogo is not robust in low memory conditions.

Fix Bug #548; BITCUT/BITCOPY/BITPASTE/BITPASTETOBITINDEX now throw errors.
Before, they showed a modal dialog boxes and threw a stopping error.

Also, if a BITMAPTURTLE has no bitmap, a message is printed to the commander, instead of showing a modal dialog box.

Add bad input tests for BITCOPY, BITCUT, and BITPASTE.
This adds the necessary regression tests for fixing Bug #548.

Add a banner comment that explains which bitmode.lgo tests.

Fix a typo of the symbolic name of a translatable string.
LOCALIZED_ERROR_BITMAPSPECIALTUTRLE -> LOCALIZED_ERROR_BITMAPSPECIALTURTLE
^^

Fix Bug #547; Throw errors from the PORT* API instead of showing a model dialog box.
This also removes an unneeded translation string for when a port cannot be closed.
This was only shown when the port was not open, for which there is a better error message.