JBasic 2.1 improves quality and performance

JBasic 2.1 is a "Fit and Finish" enhancement to the 2.0 release. Notable changes in this release include:

1. Bug fixes.
2. More control over variable and record field data types.
3. Optimizer enhancements give many programs 5-10% speedup
4. Make arrays and strings both supported by LEFT, RIGHT, etc.
5. Misc enhancements to multi-user support (see change log)
6. Updated users guide.