There is really no point in having this method.  Before it is called,
localgeodesicfefunctiontest already checks whether the derivative
is correct (by comparing with an FD approximation).  If a derivative
passes this test it MUST be tangential.  No need to check that
explicitly.

[cleanup] Move the FD approximation of the GFE function gradient from the GFE function into the test

It is a part of the test harness, and should not clutter the implementation of the
GFE functions themselves.

[[Imported from SVN: r9573]]

[[Imported from SVN: r8182]]

[[Imported from SVN: r8150]]

[[Imported from SVN: r8109]]

[[Imported from SVN: r8050]]

This is needed to test quad elements and higher-order gfe.

[[Imported from SVN: r8047]]

and hand it to all tests, rather than having each test create
its own.

[[Imported from SVN: r8046]]

[[Imported from SVN: r8044]]

[[Imported from SVN: r8043]]

[[Imported from SVN: r8042]]

[[Imported from SVN: r8007]]

[[Imported from SVN: r8001]]

[[Imported from SVN: r8000]]

[[Imported from SVN: r7998]]

[[Imported from SVN: r7411]]

[[Imported from SVN: r7347]]

[[Imported from SVN: r7310]]

[[Imported from SVN: r7302]]

[[Imported from SVN: r7301]]

[[Imported from SVN: r7141]]

[[Imported from SVN: r7140]]

[[Imported from SVN: r7138]]

[[Imported from SVN: r7137]]

[[Imported from SVN: r7120]]

[[Imported from SVN: r7119]]

[[Imported from SVN: r7118]]

[[Imported from SVN: r7115]]

[[Imported from SVN: r7104]]

[[Imported from SVN: r7103]]

[[Imported from SVN: r7102]]

[[Imported from SVN: r7101]]

This test itself is not tested yet and may still contain bugs.

Also, I out-commented the permutation-invariance test.  I have to make
sure somehow that test points are close enough together.

[[Imported from SVN: r7100]]

[[Imported from SVN: r7099]]

[[Imported from SVN: r5940]]

[[Imported from SVN: r5918]]

[[Imported from SVN: r5736]]

[[Imported from SVN: r5735]]