rename 'IO State' files to 'Connectors'

[orubel]

Have been using name 'IO State' since 2013 ... but industry has now established a name of 'connectors'. Need to rename them to fit industry standard.

I may have been first (and established an abstraction for reloading on the fly) but need to rename to industry standard so development community can commonly understand structure.

This hurts my ego a bit but it is better for community. And what is better for community is better for project... ego be damned :)