merge. update cmake.
Merge branch 'upstream' into develop
update boost dep for osx
only log mining message when hash changes
Revert "only log mining message when hash changes"

This reverts commit bed0539d7029260847837174fc8bde3bb0a82352.
Merge branch 'up-develop' into develop
Merge pull request #56 from subtly/develop

update for osx builds