Issue #980624: Set width and height of block map. Cleaner syntax and code for setting block map width and height. Add help text when setting block map width and height. Based on patch by jaakko, with edits by babbage.
Return default block map sizes to previous default to maintain compatibility with previous default installs. Place block map size configuration above additional text box, for cleaner interface. Add "Block" to labels for block map size for clarity, and standardize capitalization of label.