Start of cleanup of Proxy logging.

1. Changed names to be cleaner.
2. Arguments to logging functions are no longer optional.
3. Added TRACE.
4. __LOG*__ is now just __LOG.
5. Outputs to stderr, can be changed as a compile time option.
Updated apps_api to new logging system.
Updated friends_api to the new logging system.

1. Also did a bit of syntax cleanup while I was at it.
Slightly polished new logging system.

1. __LOG only takes one+ arguments.
2. Slight syntax cleanups.
Further improved apps_api logging.

1. Added some __LOG and __TRACE statements.
2. Slight syntax cleanups.
Added TRACE and LOGs to friends_api.
Logging and cleanup of core proxy files.

1. Updated steam_api_proxy to new logging system.
2. Initialized the global server variable to NULL for safety.
3. Updated various comments and formatting.
Updated user_api to the new logging system.

1. Also syntax fixes.
Updated userstats_api to the logging system.

1. Also syntax polishing.
2. Note that a few STUBS/similar may be print unset strings as strings
rather than pointers.