Rename "rtstool" to "cinder-rtstool", add dep

With rtstool merged into Cinder, it should use the
"cinder-" prefix.

Add to setup.cfg scripts section for installation.

Additionally, add the rtslib-fb>=2.1.39 dependency
to Cinder's runtime requirements.

Implements blueprint: lio-rtslib

Change-Id: I715db09cb86145c6769c345f59ecda4d18b5e659
Merge "Rename "rtstool" to "cinder-rtstool", add dep"