User customization export and import

[MobyGamer]

All user customizations should have a unified export and import format, with each user datum identified by the hash. This goes for flags, notes, custom command-lines, etc. Can be implemented as command-line.

Why? Because being able to export/import user customizations means they can persist across index reloads. Although this will be a PITA, it should probably be pure ASCII so that it can parsed by humans, and possibly edited/created as a way to enhance loads before users fire up TDL. JSON a pipe dream, more likely custom format.