Fix extending class in subpackage.

[yuriy-kozlov]

Use base class package name rather than module name because
MATLAB requires it to be fully qualified.

[yuriy-kozlov]

This fixes #55 or at least part of it.

[jaeandersson]

Thank you for your contribution!

[nunoguedelha]

This PR seems to break previous configurations for generating bindings, typically in simple cases where we generate all bindings for a single module, into a single package folder, both with same name. Here is an example of issue: robotology-dependencies#3.
@yuriy-kozlov @jaeandersson it would be nice to have some more details or a clear explanation of the impacts on the module definition (in the module file <module>.i) or the generated tree structure.

[nunoguedelha]

CC @traversaro

[yuriy-kozlov]

@nunoguedelha do you specify the package= option in %module? I have it everywhere and I think missing it is triggering this bug. It should be optional, of course, so I can work on a fix.

[nunoguedelha]

@yuriy-kozlov thank you, I'll try it ASAP and let you know. Of course, if you can make it optional it would be great, because in our case I think the option would be over-killing, since we always have a single module per package.

[jaeandersson]

So, should this commit be reverted then?

[nunoguedelha]

Personally, I realize I won't have time to run further tests following @yuriy-kozlov recommendations. I was hopping we could get a fix from him for making the feature optional, and so backward compatible with old configurations. Otherwise I suggest to revert the commit.