autfilt would segfault after reading any file, because the local result_
structure used in hoaparse has the same name as the local result_
structure used in dstarparse.  For some reason I can only see this
problem using clang-3.5, not with gcc.

* src/dstarparse/dstarparse.yy, src/hoaparse/hoaparse.yy: Declare both
structures in a different namespace.