added basic terminal command history

use up/down keys to navigate through command history.
minor cleanup on command history.  removing unneeded var.
Merge branch 'devel' into chriskoz-terminalHistorySupport
Slight refactoring of a PR

Corrected indentation, removed jumpy cursor, fixed off-by-one errors on history limits, limited history to a maximum of 300 entries ("300 items of command history should really be enough for anybody!")