* configure, configure.in: version 1.0.21cvs
* doc/releases.txt: minor updates for new build system
* doc/descriptions/canon_dr.desc, doc/descriptions/coolscan3.desc,
doc/descriptions/rts8891.desc, doc/descriptions/xerox_mfp.desc:
remove :new tag
* doc/descriptions/epjitsu.desc, doc/descriptions/fujitsu.desc: version
* doc/descriptions/umax1220u.desc: correct status of 1600U
* doc/descriptions/xerox_mfp.desc: status = new