Embedded interfaces in `aux_files` generate `unknown embedded interface XXX` errors. See below for example of the problem: ``` // source import ( alias "some.org/package/imported" ) type Source interface { alias.Foreign } ``` ``` // some.org/package/imported type Foreign interface { Embedded } type Embedded interface {} ``` Attempting to generate a mock will result in an `unknown embedded interface Embedded`. The issue is that the `fileParser` stores `auxInterfaces` underneath the package name explicitly specified in the `aux_files` flag. In the `parseInterface` method, there is an incorrect assumption about an embedded interface always being in the source file. ``` case *ast.Ident: // Embedded interface in this package. ei := p.auxInterfaces[""][v.String()] if ei == nil { return nil, p.errorf(v.Pos(), "unknown embedded interface %s", v.String()) } ```