Remove NimbleThread and make NimbleScaffolde derive from BasicThread.

- Following convention introduced in OpenNI
Merge branch 'master' into fix/nimble-device
Updated comment to explain having a sleep in the UnitTest.
Merge branch 'master' into fix/nimble-device
Merge branch 'fix/nimble-device' into 'master'

Remove NimbleThread and make NimbleScaffolde derive from BasicThread.

Merged-on: https://www.assembla.com/code/OpenSurgSim/git/merge_requests/1217083