started demo program shelld
added to (vicare posix) variants of select having Scheme ports as arguments
fixed license notice in macros.texi, added documentation appendix "History"
development of demo program shelld
added flhypot and $hypot
added flcbrt and $flcbrt, fixed errors for flsquare and flcube
changed $magnitude-cflonum to use $flhypot
Merge remote-tracking branch 'upstream/devel' into devel
Merge branch 'devel' into debian