[Uim] Certain keys break input

[David Oftedal]

Hi! I've noticed that certain keys tend to break off input, and, as 
happens when you input characters that aren't recognised, the input's 
reversed.

For instance, try and use uim-romaja to enter: "yoboseyo". It works 
until the second "y", but when you type that in, the previous input, 
"se", is reversed, and it turns into "yoboesyo". Apparently, uim thinks 
that "sey" is _one_ sequence, and treats it as unrecognised and reverses it.

I believe a few other keys break the input as well.

-Dave Oftedal