Great renaming: basis -> shapeset.

In particular, the classes Basis and CollectionOfBasisTransformations have
been renamed to Shapeset and CollectionOfShapesetTransformations.

The term *shapeset* denotes a family of *shape functions* defined on a
reference element. Thus, from now on, shape functions live on reference
elements, while basis functions live on physical elements. This usage is
consisted with e.g. Szabo and Babuska's and Solin's.
Removed unnecessary includes from dense_global_assembler.cpp.
Documented BasisData and GeometricalData.
Restored const keywords in methods of TestKernelTrialIntegral.
Documented TestKernelTrialIntegral::evaluateWithNontensorQuadratureRule().
Renamed DefaultTestSingleScalarKernelTrialIntegral to
TypicalTestScalarKernelTrialIntegral and documented it.
Documented the shapeset classes from Fiber.