What's new in version 9:
* Implemented the RND instruction, which initializes the pseudorandom number generator with the current timer value and returns a result if its parameter is zero, returns a new result with the current initialization if the parameter is positive, and initializes the pseudorandom number generator with its parameter if it's negative. (NOTE: for now, the values of the pseudorandom numbers will not coincide with those generated on a physical C65, even though the effect of the instruction as described in the manual is reproduced to the letter, because the standard srand() and rand() functions of C are used, rather than the formula from the original BASIC 10.)
* Extended the default expression evaluator, to support negative numbers or variables as parameters for mathematical functions.
* Added checks in the Let, If, Input and Print functions to prevent the user from using variables called DO, FN, GO, IF, ON, OR, TO (which would be tokenized as commands and prevent the program from working).
* Fixed a bug in the Next function, which used to make it exit loops after a single iteration if a colon was present after the corresponding FOR instruction
* Extended the Dim function so that multiple arrays, separated by commas, can be declared with a single instruction.
* Fixed a bug in the function that transforms expressions into a format MuParser can understand, which used to work incorrectly with negative variables being multiplied, divided or elevated to power.
* Fixed a bug in the keyboard input routine, that used to make the character display sluggish on Windows 10.