update Makefile.am with new files and renamed files

split life.hpp into lifemacros.hpp, lifeversion.hpp and lifeassert.hpp

allows LIFEV_ASSERT( cond).error("")

Fixed a bug. When changing SolverAztec's matrix a segmentation fault took place. The problem was fixed by creating an instance of the linear solver inside the timeAdvance() member, but it should be further investigated.

Now recompute both the stabilization and the advection term at every time step. Needed to obtain the proper scaling of stabilization parameter.

  weighted according to advection velocity
* fixed some typos in comments and messages

  ( type: ( a - b == 0 ) instead of ( a - b ) == 0 )
* improved readability of source code and error messages

* some cosmetics

* use backward Euler instead of BDF2

* preparing scaling with velocity (commented)

points...

* removed accessor for Dof (is already inherited from HyperbolicSolver)
* improved documentation
* cosmetics

* cosmetics

Hope it will help!