configure: reduced some warnings on gcc flags
dvdnav: added dvdnav/dvdread submodules
conf: honor disable_system_conf (except stream_dvb)
win32: disable_system_conf defaults to 1 on win32
configure: added --with-arch and --with-tune overrides
sherpya's customizations
configure: enabled support for libmodplug in lavf
stream_cddb: fix include path on MinGW-w64
vcd support on MinGW-w64