Improvement: Make runtime issues to compile time errors

[rainman110]

I thought about this a while. I'd really like to make sure, that the issues you had memory wise should be catched already at compile time. I found a very simple solution to it:

In the arguments of the swig headers, we don't use opencascade::handle. Instead we use a new unknown type e.g. OccHandle_XXX. This type is only known, if it was defined in the other module.

A concrete example:

BRepBuilderAPI.i:

import Geom.i

BRepBuilderAPI_MakeEdge(OccHandle_Geom_Curve curve);

Geom.i

%wrap_handle(Geom_Curve)

#define OccHandle_Geom_Curve opencascade::handle<Geom_Curve>

class Geom_Curve
{
...
};

I tried this just now, and it seems to be working. When you don't include Geom.i, you'll get a compiler error.

[rainman110]

Using this technique, I already found many missing imports. I'll try to make compiling successful, then I send you a list of missing imports.

I also found some cyclic imports, e.g. in standard.i. we probably need a better way to determine module dependencies.