build fix

error: missing 'typename' prior to dependent type name 'RelationMap::iterator'
build fix

error: expected a qualified name after 'typename'
build fix

error: expected a qualified name after 'typename'
build fix

warning: enumeration values 'AV_SAMPLE_FMT_NONE' and 'AV_SAMPLE_FMT_NB' not handled in switch
Merge pull request #6 from themalkolm/build-fix

mac build fix