issues/361: Metrics window text input keypress behaviour normalised

Up/Down continue forward and backward through the kerning list even when
a number is encountered.

Loading a word list with "quoted text" in it will keep that text as a single line
instead of splittinig it into two lines when the space occurs.
Merge pull request #420 from monkeyiq/2013march/issues/361

issues/361: Metrics window text input keypress behaviour normalised