buildout: exclude jingodf -- failed to install opster
tox/py25,jy25 ssl problem workaround (close #118)

see https://bitbucket.org/hpk42/tox/issue/91/python-25-support
buildout: migrated to version 2 (close #116)
hwp5html: do not try to extract missing BinData (close #119)
remove oxt related configs from buildout/tox
add buildout-oxt.cfg and tox-oxt.ini