dist: add support for "make dist" with out-of-source build
dist: add support for "make dist" with out-of-source build

groonga/groonga,groonga/groonga,kenhys/groonga,groonga/groonga,kenhys/groonga,groonga/groonga,groonga/groonga,groonga/groonga,kenhys/groonga,groonga/groonga,kenhys/groonga,kenhys/groonga,kenhys/groonga,groonga/groonga,kenhys/groonga,kenhys/groonga