vp8_decoder: configure.ac now checks the existence of libvpx.
vp8_decoder: coding standards
minor fixes: coding standard
libtizonia: added an AAC audio port (closes #72).
libtizonia: fixed various coding standards issues in (mostly) port classes
aac_decoder: component now links against libfaad2.
libtizonia: fixed a nasty typo in the binary port constructor.