Add CMake buildsystem, fix sources to compile

The provided Makefile does not work for me:
```
ondrej@eagle:~/repos/classic/tests/advection(cmake)$ make
Makefile:57: /src/Makefile.common: No such file or directory
make: *** No rule to make target `/src/Makefile.common'.  Stop.
```
so this PR implements a CMake build system. Now it builds, thought here are lots of warnings and errors. This PR fixes all errors, so that sources compile. The warnings are:
```
ondrej@eagle:~/repos/classic(cmake)$ make
Scanning dependencies of target classic
[  6%] Building Fortran object src/CMakeFiles/classic.dir/utils.f90.o
[ 12%] Building Fortran object src/CMakeFiles/classic.dir/clawdata_module.f90.o
[ 18%] Building Fortran object src/CMakeFiles/classic.dir/precision_module.f90.o
[ 25%] Building Fortran object src/CMakeFiles/classic.dir/1d/solution_module.f90.o
[ 31%] Building Fortran object src/CMakeFiles/classic.dir/1d/geometry_module.f90.o
[ 37%] Building Fortran object src/CMakeFiles/classic.dir/1d/solver_module.f90.o
/home/ondrej/repos/classic/src/1d/solver_module.f90:251.57:

            call set_boundary_conditions(solution,solver)
                                                         1
Warning: Procedure 'set_boundary_conditions' called with an implicit interface at (1)
/home/ondrej/repos/classic/src/1d/solver_module.f90:254.45:

            call before_step(solution,solver)
                                             1
Warning: Procedure 'before_step' called with an implicit interface at (1)
/home/ondrej/repos/classic/src/1d/solver_module.f90:258.75:

                call source_term(t_old, solver%dt / 2.d0, solution, solver)
                                                                           1
Warning: Procedure 'source_term' called with an implicit interface at (1)
/home/ondrej/repos/classic/src/1d/solver_module.f90:262.49:

            call hyperbolic_step(solution,solver)
                                                 1
Warning: Procedure 'hyperbolic_step' called with an implicit interface at (1)
/home/ondrej/repos/classic/src/1d/solver_module.f90:267.82:

         call source_term(solution%t + solver%dt,solver%dt,solution,solver)
                                                                           1       
Warning: Procedure 'source_term' called with an implicit interface at (1)
/home/ondrej/repos/classic/src/1d/solver_module.f90:269.98:

urce_term(solution%t + solver%dt * 0.5d0,solver%dt * 0.5d0,solution,solver)
                                                                           1                       
Warning: Procedure 'source_term' called with an implicit interface at (1)
/home/ondrej/repos/classic/src/1d/solver_module.f90:156.24:

        self%limiters = clawdata%limiters
                        1
Warning: Possible change of value in conversion from REAL(8) to INTEGER(4) at (1)
[ 43%] Building Fortran object src/CMakeFiles/classic.dir/1d/rp1_interface.f90.o
[ 50%] Building Fortran object src/CMakeFiles/classic.dir/1d/before_step.f90.o
[ 56%] Building Fortran object src/CMakeFiles/classic.dir/1d/hyperbolic_step.f90.o
/home/ondrej/repos/classic/src/1d/hyperbolic_step.f90:108.45:

                             solver%limiters)
                                             1
Warning: Procedure 'limiter' called with an implicit interface at (1)
/home/ondrej/repos/classic/src/1d/hyperbolic_step.f90:115.16:

                f(m,i) = f(m,i) + 0.5d0 * abs(s(mw,i))      &
                1
Warning: The FORALL with index 'mw' is not used on the left side of the assignment at (1) and so might cause multiple assignment to this object
[ 62%] Building Fortran object src/CMakeFiles/classic.dir/1d/set_aux.f90.o
[ 68%] Building Fortran object src/CMakeFiles/classic.dir/1d/boundary_conditions.f90.o
[ 75%] Building Fortran object src/CMakeFiles/classic.dir/1d/limiter.f90.o
[ 81%] Building Fortran object src/CMakeFiles/classic.dir/1d/qinit.f90.o
[ 87%] Building Fortran object src/CMakeFiles/classic.dir/1d/source_term.f90.o
Linking Fortran static library libclassic.a
[ 87%] Built target classic
Scanning dependencies of target main
[ 93%] Building Fortran object tests/advection/CMakeFiles/main.dir/rp1_advection.f90.o
[100%] Building Fortran object tests/advection/CMakeFiles/main.dir/main.f90.o
Linking Fortran executable main
[100%] Built target main
```
Some of them seem to reveal real problems in the code, for example the `self%limiters = clawdata%limiters` one.
The fact that the code uses implicit interface is very bad, because the compiler can't check the types. This should not be used in modern Fortran. The solution is to at least provide an interface block and import this block, or (better) move all global subroutines into modules and import the modules.

When I try to run the test:
```
ondrej@eagle:~/repos/classic/tests/advection(cmake)$ ./main 
*** in opendatafile, file not found:./setprob.data
```
It fails due to missing input file. 

Another problem is that the `main.f90` file is referencing `controller_module.f90` which is not in the repository, so i had to comment it out, together with `run_simulation()` which I assume is declared in it.

@mandli, could you please review this?