Cactus doesn't add include paths to F90-compilation

[Frank Löffler]

Cactus doesn't add include paths to F90-compilation, probably because those files get preprocessed anyway in an extra step. However, this then also neglects the include files necessary for F90-modules. The attached patch adds include-dirs also as compiler flags to let it find the modules.

Keyword:

[Frank Löffler]

I should add that this is not so much a problem for thorns depending on other thorns, because all of that is compiled in one place with the .mods being there. However, thorns might depend on external libraries with fortran bindings - compiled by Cactus, including .mod files. This is where the current situation breaks.