Spinning cursors (10 patterns now) are configurable in text.dat

Inspired by the cool progress cursor displayed by 'git-size', the spinning
cursors in the Synchronet terminal server are now configurable via text.dat
strings (SpinningCursor0 - 9), no maximum length.
Increased the cursor "spin" rate from 4 to 5 times per second.
The first character of the spin pattern is chosen at random between 0 and 4
but the direction of increment is also from left to right.