There were problems with putting e_os.h just into the top directory,
because the test programs are compiled within test/ in the "standard"
case in in their original directories in the makefile.one case;
and in the latter symlinks may not be available.
1. The already released version was 0.9.1c and not 0.9.1b
2. The next release should be 0.9.2 and not 0.9.1d, because
first the changes are already too large, second we should avoid any more
0.9.1x confusions and third, the Apache version semantics of
VERSION.REVISION.PATCHLEVEL for the version string is reasonable (and here
.2 is already just a patchlevel and not major change).
tVS: ----------------------------------------------------------------------
