Move the '1:' to outside the user-selectable portion of the map's fractional scale box

[wayfaringrob]

The '1:' portion of your fractional scale does not change. Even if you wanted to get clever and try typing a scale like 2:700, it doesn't accept it. The '1:' portion, then, could be moved to the left of the typing area/dropdown. The box already accepts entries such as '500000' to mean 1:500,000, so moving the 1: to a static portion of the toolbar would help when trying to select from the left side of the string. It's easy to select the : when you don't want to, which results in your scale value being multiplied by an order of magnitude.