DeCSA.h: remove unused defines
Add a validity time for a keys

Set a timestamp when OSCam provides a CW for a given index,
this allows to detect if key is invalid.
Now even hardware CAMs and dvbapi can cooperate on the same
device.
Put the git tag into the version name

If the plugin is built directly from the .git repository,
put the git tag into the version name.
Fix a performance regression in decryption

Do not call Decrypt() for clear TS packets.