Pathways branch update to v0.4

[Fred Kingham]

Hi all,

 pathways has moved on to 0.4 for the default branch. Its alphaware, although its coming along nicely.

The changes in this release make pathways validate forms in a similar way to the rest of opal.

 It also changes some defaults to hopefully more sensible ones... Non-singleton models now appear by default in the pathway as an one to many.

 Development on this release is still ongoing. However does contain significant improvements. Some api changes have occurred, please check the CHANGELOG.md for the changes. 

 Thanks,

 Fred