[algorithms] Overlap interface revision

* Now it accepts not only binary files, also ROI files with multiple
  labels.
* Volumes can be handled in voxel units (as formerly) and mm3
* Keeps backwards compatibility of outputs and inputs
fix: topup when out_base is a path
Update test functions BEFORE tests
remove deb packages installation
Fixed tests.
Merge remote-tracking branch 'upstream/master' into makefile
Fixes #933
Conmat test function
Added xor parameter for robustness
moved the import inside the constructor
added no dep install version. we'll be testing on both.
fixed bash conditionals
another attempt at fixing bash conditionals
Add tests
tiny typo
Merge pull request #934 from chrisfilo/fix/travis

WIP: fixing travis
Merge remote-tracking branch 'origin/pr/936'
fix: change where nlmeans check is made
Merge remote-tracking branch 'upstream/master' into fix/topup

* upstream/master: (82 commits)
  tiny typo
  another attempt at fixing bash conditionals
  fixed bash conditionals
  added no dep install version. we'll be testing on both.
  Added xor option in Camino connectivity for robustness
  Conmat test function
  Added more connectivity matrix options in Camino interface
  Fixed tests.
  remove deb packages installation
  added apt caching
  fix: d3 change.
  switched to six.string_types for string type checks
  added external package: 'six'
  Mention AddNoise in the changelog
  Remove d3.min.js dependency
  Log cleanup
  Fixed tests
  Update README.rst
  Update links_names.txt
  Update index.rst
  ...
Merge pull request #925 from oesteban/enh/OverlapOfROIs

[algorithms] Overlap interface revision