FMSLogo Code

Refactoring: Combine boolean (is binary) with wxBOM (character encoding) into ENCODING.
This enables a clearer discription of a file stream's encoding requirements, as it
didn't make sense to use a BOM to describe a binary encoding.

Add infrastructure to keep character encoding with a FILE*.
This is an attempt to be able to read/write Unicode text while
maintaining a reasonable amount of backward-compatability.
A lot more work is needed to make the file API compatible with Unicode.

Merge in changes to print functions from trunk.

Refactoring: Rename new_line() to print_newline()
This more clearly explains what it does.

Refactoring: Extract function for printing a string.
- remove duplicated logic
- improve performance by replacing ndprintf() when format string had no format parameters

Refactoring: inline print_nobrak()
This removes one of the many confusingly-named print functions.

Merge changes from trunk.

Fix a copy&paste error in a function comment

Add another example to the documentation for BACKSLASHEDP.
This one shows that being between vertical bars isn't sufficent to be backslashed.
The character must also change its semantic meaning.

Extend data range for READCHARS to include control characters.
The Unicode FMSLogo does not prevent ASCII control characters from working correctly.