"u" alias

[Tom Tromey <tromey@cygnus.com>]

Tonight I discovered that the command "u" is an alias for "until".  I
don't like this.  I've literally never used the "until" command.
However, I do use the "up" command every single time I run gdb (I
can't remember not using it), and I expected "u" to alias "up" by
default.  Can we change this?

This is ancient code, so I'm sure I'll hear the "somebody relies on
this" argument.  But does anybody really?  Can we take a poll or
something?

Tom