Thread improvements:
* Thread logging: introduce monotonically increasing thread index,
  printed just after the pid in the log in place of the useless class
  name. Class name and index are now printed at thread creation time.
* detail::ThreadID in separate header to share between thread & threadID
Work for Eyescale/Collage#40:
* Structure to gather compression results
* boolean operators for (De)Compressor
* Array moved here from Collage
Fix some deprecation warnings
CR #85
CR #85
CR #85
Merge pull request #85 from eile/master

Fix some deprecation warnings, Work for Eyescale/Collage#40, Thread improvements