Style related fixes and other minor edits

Including things such as:
 - Fixing quotes in command related files
 - Removing trailing whitespace
 - Making consistent the use of spaces around operators and preincrement
 - Using simpler expressions for some code ([example](https://github.com/kotarou3/Pokemon-Showdown/commit/071863d9f8de3a79e17537f4edd29f55480726c2#diff-4e71f9f8fa7dc574ad692d530284d882L98))
 - Removing obsolete code ([example](https://github.com/kotarou3/Pokemon-Showdown/commit/727c3a8ffe64479d68752e47e9714c65ea50eb32))