+== variable parameters description default
+ --with-jobs=n: n = parallel build jobs 1.5*cpus+2
+ --exec-name=<app> app = binary executable name cin
+ --with-cinlib=lib lib = cinelerra library path $libdir/$app
+ --with-cindat=dat dat = cinelerra share path $datadir/$app
+ --with-config-dir=cfg cfg = .bcast config dir $$HOME/.bcast5
+ --with-plugin-dir=plg plg = plugin install dir $cinlib/plugins
+ --with-ladspa_dir=lad lad = ladspa install dir $cinlib/ladspa
+
+$var represents configure shell value
+$$ stuttered represents as makefile data = $