Added QtTesting to the Open Chemistry superbuild

This will be used in Avogadro, MongoChem and MoleQueue for testing
automation.

Change-Id: Id04f1e7df4753f10b280f387f5c3a1e767688874
New top level options for docs/testing

Added top level options to enable testing or turn on documentation
building. This makes it easier to do for all Open Chemistry projects.
Also removed the runtime and library output directory overrides from the
top level - it was causing erronous warnings from CMake and when working
on individual projects having individual binary directories for each
project seems more intuitive.

Change-Id: I42ebf16ba9df19a205b2e6c326e9b099fbe3176d
Tarballs should unpack source in the bin dir

Additionally have VTK use the standard arguments variable.

Change-Id: I52274542f49f10395c6098a6bdd5745a5b6c3ff9
Added a FindEigen3 from Eigen 3's source tree

Change-Id: I8f514b0afe461356b0df02c9de03d047c9302544
Merge topic 'submodule-updates' into master

363fbff4 Added a FindEigen3 from Eigen 3's source tree
a75dd84a Tarballs should unpack source in the bin dir
06cf3286 New top level options for docs/testing
35c26479 Added QtTesting to the Open Chemistry superbuild