wrap_c generating incorrect signature for typedef'ed pointers

[tk3369]

This is an issue similar to #152. See this discourse post for more details.

Example:

typedef struct {
    double x;
} FOO, *FOOP;

FOOP test1(double a, double b, FOOP c);

got wrapped as:

function test1(a::Cdouble, b::Cdouble, c::FOOP)
    ccall((:test1, test), FOOP, (Cdouble, Cdouble, FOOP), a, b, c)
end

Expected result should be:

function test1(a::Cdouble, b::Cdouble, c)
    ccall((:test1, test), FOOP, (Cdouble, Cdouble, FOOP), a, b, c)
end