Fixed bug where typedefed Eigen and OpenCV Types are not recognized.

[KarlKulator]

E.g:
using Matrix2 = Eigen::Matrix2f;
Matrix2 mat;

-> mat could not be plotted previously

[brunoalr]

@csantosbh could this be done somewhere else instead of in the example types?

[csantosbh]

@brunoalr good point. I'm working on a mac+lldb port that defines a clear and concise interface for the "symbol" object provided to the giwtype and want to keep it as simple as possible (since this makes it easy to add support for other debuggers). I presume that the "strip_typedefs" method is part of GDB's interface, so we could have a support string processing module that does this kind of stuff.