Patch-level release 1.16.5

This release:

• increases the return stack size of the main task from 1 KiB to 2 KiB.
• removes an unnecessary instruction from if, while, and until, resulting in smaller and faster code.
• adds an optional 'glob' tool in extra/common/glob.fs.
• adds a 4x8-pixel font, which can be used with the PicoCalc amongst other things.