Added an implementation of RQ decomposition using Givens rotations.
The implementation currently only support 3x3 matrices.
Added Gander::areClose() which compares two Eigen classes and returns true if they equal within a tolerance.
Removed GanderTest::areEqualWithAbsError.
Added a validation check into Gander::decomposeRQ3x3.
Renamed GanderTest::randomAngle to GanderTest::randomNumber.
Added comments to GanderTest::DecomposeRQ3x3Test.
Added more tests to EigenTest::GeometryTest.
Extended the decomposeRQ3x3 test cases.