PR: Fix vars2fortran: No typespec for argument when compiling HELP3O

[jnsebgosselin]

Fixes #24

When compiling the Fortran code for HELP, we get a lot of warnings of the type :

{}
In: :HELP3O:pyhelp/HELP3O.FOR:ahu
vars2fortran: No typespec for argument "m".

This means that the typespec of the function variables need to be defined explicitly in the code. The goal of this PR is to fix that by declaring explicitly the variables in each function that raises a warning. This need to be done very carefully and rigorously though not to introduce unwanted errors in the computation.

Below is a part of the log from AppVeyor during the building process: