deprecate getch() -- term.inkey() should be used.

[Jeff Quast]

getch() is from an era where blessings did not have keyboard support. Now that we use my fork, 'blessed', term.inkey() is much more suitable interface. However, much of the UI and default board scripting elements still make use of getch(), so we cannot remove.

Slated for warnings.warn deprecation sometime in 2.x release, and removal in 3.0