Added lcdClear and lcdPrint CLI functions

[etomzak]

lcdPrint prints text to the display. Printing based on character codes is supported. lcdClear clears the display.

[haata]

Oh, neat!
This may take me a bit to merge, but it's definitely something I was planning for the LCD :D

[etomzak]

I'm happy to make changes, additions, code style tweaks, etc. There's so much that could be done with displaying text. I just tried to implement the absolute bare minimum.

[haata]

Please use uint8_t/uint16_t/uint32_t.

[etomzak]

I've fixed the code style issues.

A systematic way for converting fonts sounds like a great idea. I hand-converted this first set of characters to have something to display, but it really isn't a sustainable way of doing it.

A couple of things I was thinking of when I was putting this together:

• Storing fonts in memory the way I have done seems unsustainable. A user might want to have access to several fonts in various styes and resolutions. An ErgoDox could display 32x32 characters, but these need 16x more memory than the 8x8 set. Some way of dynamically selecting and loading fonts from flash could be useful.
• Is there a better way to draw to the display than over TTY? Some days it works great, but sometimes it drops data. I wonder if there's a more resilient way of talking to the keyboard.

I might be up for contributing some font conversion code. It could be the reason I need to finally learn python :P