Added a new lock to prevent a crash related to multi-thread.
Fixed a silly bug to filter out all listlinks during generating subset of a big corpus
Added interaction information calculation.
Fixed splitting disconnected subpattern into connected subsubpatterns
Tried to not use H-Tree
Filter out the patterns that have links only contain variable nodes.
Fixed a sign (negative or positive) in ii calculation.
Added another small test corpus and conf example for wiki tutorial.
Merge pull request #1003 from shujingke/PM

Implemented Interesting pattern mining by evaluation of Interaction Information.
Added options in the pattern miner example config file.
Added options in config for if enabling frequent/interesting pattern mining, using interaction information or surprisingness evaluation.
Merge pull request #1005 from shujingke/PM

Added options in config for frequent/interesting pattern mining.
New OpenCog docker file - AvdP
Merge pull request #1006 from Alex-van-der-Peet/master

New OpenCog docker file - AvdP
Replaced lxtask with lxde
Merge pull request #1007 from Alex-van-der-Peet/master

Replaced lxtask with lxde