Benchmark encoding translated messages as binary, too.

Results for all of my trace files:

> ./compare_sizes.py ~/ownCloud/OpenXC\ Traces/peplin/**/*.json       1
For the 89 trace files given...
Total transferred raw JSON size is 13.3MB
Total transferred raw binary size is 2.1MB
Total transferred translated JSON size is 791.0MB
Total transferred translated binary size is 318.6MB
Total transferred JSON size is 804.3MB
Total transferred binary size is 320.6MB
Binary encoding is 84.328494% smaller than JSON for raw messages
Binary encoding is 59.727489% smaller than JSON for translated messages
Binary encoding is 60.133196% smaller than JSON overall