Commit 1000! Doing the LCD performance benchmark numbers correctly.

1. The HD44780 putchar() will blank lines on carrage-return on wrapping.
A set_cursor() avoids this in the benchmark.
2. Use RTC instead of Watchdog for better measurements.
3. All and all this boosts the driver to a new level; +50% on fps in 4-bit
mode.
4. New I2C optimization gives over +60%.