remove pretenses of supporting projects on stdin

this may have worked a decade ago, but now it only produces funny
Makefiles (and needs hacking main.cpp). the feature doesn't seem *too*
important, so just clean it out.

Change-Id: I50a60b0e30341f0b523e4a5731c770c9c1013f8b
Reviewed-by: Daniel Teske <daniel.teske@nokia.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@nokia.com>