[CMake] Fortran

[Maik Beckmann]

Hello CMake people

I pushed myself during the last weekends to get more familiar with CMakes 
codebase.  Not for fun only ;), but make me smart enough to sketch an 
approach for handling fortrans module dependencies.

Bill, Brad, Alex ... it would be very nice if you're take a look at
 - http://www.cmake.org/Wiki/CMake_Fortran_Issues#Introduction_to_the_problem
 - http://www.cmake.org/Wiki/CMake_Fortran_Issues#Abstract_solution
 - http://www.cmake.org/Wiki/CMake_Fortran_Issues#Concrete_solution

I did some wild proof of concept coding, but its not ready be shown so far. 
(see the class definitions at 
http://www.cmake.org/Wiki/CMake_Fortran_Issues#Concrete_solution)

Howevery, the process of
 - parsing sources and make the information persistent
    -> -E fortran_module_scan
 - reload the information and generate depend.make
    -> -E cmake_depends using the persistent information
works for a simple exe-target with an arbitrary number of sources involving 
modules.  The next thing is to handle modules provided by another target in 
the sourcetree.

For convenience I'm temporary using boost.serialization for the persistent 
part. If the hole thing is in shape I will work cmakeish solution.

The hardest thing for me is to decide how to alter the way Makefile(2) is 
generated i.e. where to trigger the module extraction.  Some advice on this 
would be very helpfull.

I will do best to apply your advises. ASAP I will provide a patch to make this 
issue less abstract.  

Best, 
 -- Maik