Datasort, defrag, caching, documentation and CI

[SaveTheRbtz]

This pull request mostly described in 23b5487:

Most changes can be summarized as: * Replaced defrag with data-sort routine: it's responsible for defragmentation, index and data sorting.

• Added binlog layer that can copy all data modification for specific base to binary log and then apply records to another one.
• Added travis-ci integration (pun intended).
• Added Doxyfile for Doxygen autogenerated documentation.
• Removed unused routines like Atomic and ThreadSpinlock.
• Removed caching of on-disk entries. * Renamed test_datasort to eblob_stress * Moved documentation to doc/

Datasort and Binlog functionality is described on reverbrain's wiki's blueprints: http://doc.reverbrain.com/blueprints:eblob:data-sort http://doc.reverbrain.com/blueprints:eblob:binlog