Merge pull request #27 from fxdupont/wrap0

prepare for wrap key support
Merge pull request #28 from fxdupont/getobjectsize

improve C_GetObjectSize
Merge pull request #29 from fxdupont/digestkey

implement C_DigestKey
Merge pull request #30 from fxdupont/visibility2

add missing m4/acx_visibility.m4 file
Merge pull request #31 from fxdupont/memory

fix severe memory leak