Allow copying of decrypted files

[jordanisaacs]

Issue

Some services don't allow the use of symlinked files. Therefore they need to be copied.

Solution

Two options: cpOnActivation = [ ] and cpOnService = [ ] that take absolute paths. They copy the decrypted file on activation or on service respectively. This is because the copy if done to the normal file system does not need to be performed during runtime and thus a systemd service would not be needed.

Note: these copied files will never be deleted automatically until cleanup is implemented.

Progress:

• [ ] cpOnActivation
• [x] cpOnService - Finished in commit