Advanced Build Mode: Separate remove/build sizes + Allow typing of numbers

Hi, so this is a multi-part suggestion aimed to help with server lag and also playability of the game when building with the advanced builder. One suggestion is to give more control to admins to moderate lag, another is to help assist players in building and removing blocks with less tedium, and the final suggestions are to add more ease of use to the advanced build menus.

1: Allow the ability to set different maximum values for removing and adding chunks of blocks in the advanced build...

Advanced Build Mode: Separate remove/build sizes + Allow typing of numbers