update issue #36 
added mortar space definition `Moch<N>()`
still lots of work to do and in particular allowing to go through the dof
table without hardcoding the type of finite element. In hp or mortar methods
the polynomial order changes in the elements
update issue #36
updated mortar test
added begin() and end() free function to iterate over mesh entities using
range for loop c++11 construct
fix internalElements()
add subclass for sub-space (Pk-1) construction
 - make local dof dynamical : allow for different  polynomial order in elements
 - added begin() and end() free function to iterate over mesh entities using
 range for loop c++11 construct
new constructor
ignore