Backspace does not work consistently in "New Footprint" dialog

[John Beard]

Version 2014-04-11 BZR 4798, Built on Linux Mint 16

When entering a name in the "New Footprint" dialogue, the backspace key do not work consistently.

For example, after entering capital letters, such as "BAR", upon backspace, nothing happens. However, if the Pcbnew window then loses focus, the update (losing the "R") is applied, and the text now reads "BA". When regaining focus, backspace works again until more capitals are entered entered. All-lower case letters (e.g. "bar") work without focus loss, mixed case (e.g. "Bar") do not.

Additionally, on loss of focus the backspace is applied in the wrong place, e.g. "BAR_<backspace>1<switch focus>" will result in "BAR_", not "BAR1" as you might expect.