version 9.1

• bumped required 64tass assembler version, older versions didn't assemble some generated code correctly
• new way of prefixing all symbols in the generated assembly code (p8_ prefix)
• syntax parsing improvements: '{' can now be placed on next line, comments and whitespaces allowed in array literals, added /* .... */ block comment
• added math.atan2() and math.direction() routines to calculate angles, see them in action in the new cx16 spotlight example
• uword var == string is now also accepted as syntactic sugar for a string.compare call
• cx16: added diskio.curdir()
• cx16: added cx16.save_virtual_registers() and cx16.restore_virtual_registers() to help save/restore R0-R15
• fixed a couple of for loop and repeat loop code gen errors
• improved some error messages
• some performance improvements in generated code
• fixed problem in diskio.diskname()
• fixed several compiler and code generation bugs
• improved documentation
• IR and VM improvements