instead I've picked "enc", because that's what's in the prototypes.
("_encrypt" is reserved only as an external name, but still
using it in an application doesn't look like good style to me --
and it certainly isn't if the point is just avoiding shadowing,
which is apparently why the previous name "encrypt" was changed.)
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: ----------------------------------------------------------------------
