Because I just know someone's going to complain about watchlists/RC being cluttered...

Because I just know someone's going to complain about watchlists/RC being cluttered up by 'X bytes' instead of 'X', for the moment I'm splitting this to use the new rc-change-size message, and leave it at '$1' by default (so no change from the old behavior, showing number alone).

One could stick in the labeling if one desired, or leave it blank.