The cache isn't cleared properly because unlink() doesn't remove the
cache entry which caused side-effects when reusing the same file name
(which randomly happens when time() returns the same value)
This fix first makes sure the unit tests don't fail any more.
The unlink() case with the cache will be investigated separately.
Backport of f09c19c to stable6
If the file does not exist, realpath() returns false and "include false;"
produces "Failed opening '' for inclusion" which is a useless error message.
'include' works just fine with symlinks, "./" and "../".
- Added methods for sealing data with multiple keys
- Added method for encrypting data, generating iv and keyfile, and returning both
- Added 6 unit test cases (containing 12 tests) for Crypt class
- Commented out old unit tests for now
