FMSLogo Code

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

Fix a bug in FILEEXISTS that caused it to return FALSE if the file existed, but was already open for reading by FMSLogo.

Replace a hack of using SETTIMER/WAIT to force a queue check with EVENTCHECK.
This is what EVENTCHECK is designed to do.

Uppercase a use of ?REST in the example.
This was done for conformance to the style guide.

Add a missing line break.
This keeps with the convention of one sentence per line.

"That is" -> "For example"
The statement introduced an instance of a truth stated by the previous sentence, instead of restating the truth in different words, so "for example" is more approriate than "that is".

Uppercase VOWELP in the example.
This was done for conformance to the style guide.

Improve implementation of VOWELP in the example
Using MEMBERP instead of a chain of IF instructions is more in the spirit of Logo.

Remove the sentence about multiple parallel slots (copy&paste error)
FILTER does not support multiple parallel inputs.

Remove unneeded parens from FIND example.
This makes the example look cleaner.