FMSLogo Code

Fix a bad translation of "such that".
It replaces "tal que" with "de modo/manera que" or completely rewrites the sentence.

Translate the documentation for the bitmap procedures into Spanish.
This translation is based on Rosario Ruiz's translation of the MSWLogo manual.

Add a missing period to the end of a sentence.

Initialize a NODE** to NULL instead of NIL.
NIL is a typed NODE* that means "empty list" has no meaning for any other pointer.
NULL means "not yet set".

Fix bug #497; (1 2) no longer crashes FMSLogo.
The problem was that parenthesizing/treeifying the expression
failed, since 1 is not a procedure and therefore FMSLogo doesn't
know how many parameters it should take. The "tree" of 1 was
then dereferenced to get the "car" field, which crashed.

The fix, which copied from UCBLogo, is to use the tree as-is
if it's not a list (that is, don't dereference it). This results
in a "i don't know what how to 1" error, which I think is the
correct error for such an expression.

Remove contradictory information.
The documentation had previously stated that BURIED output all *unburied* items.

Fix typo: "asked to bury a procedure" -> "asked to unbury a procedure"
Of course, you can't ask UNBURY to bury anything.

Fix Bug #382; WINDOWFILEEDIT no longer crashes if the file cannot be read.
Instead, it throws a file system error if the file cannot be read.
In the screensaver, it always throws the file system error, regardless of if the file can be read.

Remove trailing whitespace

Automate enough of the regression test for bug #20 to bring it into the full test pass.