FMSLogo Code

Remove some redundant computation from mend_strnzcpy

Remove some redundant computation from clearvbar_strncmp

Rename "noparity" to "clearvbar" for clarity.

The "no parity" dates back to when UCBLogo was pure ASCII and the backslashed-ness of a character was stored in the high bit of an 8-bit byte, sometimes called the "partiy bit" when dealing with hardware. However, FMSLogo has never used the "parity" bit for this and instead marked a backslashed character by moving character to a different place in the ASCII code page (analogous to shifting them all to 128-255 by setting the high bit). Now that FMSLogo uses Unicode, it's even further removed from using a "parity" bit, as the characters are now moved to a "private use area" of Unicode.

Refactoring: Extract a global variable UTF8_BOM
This is a clearer name than "buffer".
The linker should remove duplicates.

Note that DRIBBLE files are now written in UTF-8.

Fix a bug where commands run from the UI didn't write a newline to the DRIBBLE file.
This was a regression introduced by supporting Unicode.

Fix Bug #329; SAVE and LOAD preserve words with CHAR 0, CHAR 13, CHAR 26, and CHAR 29.

The fixes for CHAR 13,26,29 were implemented by the Unicode feature, which enabled moving the "vbarred special characters" from the ASCII control characters to a Unicode Private Use Area.

This change fixes a remaining problem for CHAR 0, which is that NUL was treated as a string terminator by the parser. Now, the parser determines the end of the string by its length, not by a sentinal character. Suprisingly, this makes the code simpler (fewer lines) and removes a KLUDGE comment that has existed since UCBLogo.

Fix misspelling of "boundary" in a comment

Update the test results based on recent bug fixes and test additions.

Fix an off-by-one bug in the un-vbarring logic.
This is a regression introduced by recent refactoring.