[test.fem_projection] moved to playground
* is not going to be compiled in its current state
* stuff includes are out of date
* fem includes are out of date
[test.df_heterogeneous_projection] fixed function name
[test.df_heterogeneous_projection] moved to playgroung
* fem includes are outdated
* fem usage is outdated
[functions] minor fix
[functions.pdelabadapter] fir pdelab guard
[test.functions_norm] fixed some names and includes
[test.functions_norm] moved to playground
* pdelab usage outdated
[test.la_container] moved factory to separate header
[test.la_solver] update