Logging reworked, and related cleanup.

- Parameters to --log simplified, no longer using regex but simple subsystem and level names.
- Fixed some random logging errors with songparser messages that weren't properly flushed.
- Added selectEnum helper function to integer-enum ConfigItems.
- pathBootstrap() behavior changed so that it can be used without logging, pathInit() now prints all the debug info.
- Added getLogFilename() and getSchemaFilename().