Implement the generic mini-keystore for security.

1. We will progressively migrate to this implementation.
2. For richc to have a quick review on the keymgmt part.
3. Add remove_key and make sure all functions are working.
4. Add permission check for get operation.
5. Return the retry count if unlock failed.
6. Add the reset operation for keystore reset.
7. Add the putfile shell command for putting the key value from file.
8. Fix the boundary issue during parsing command.
9. Use the ' ' as delimiter and reset the reply structure for each request.
10. Add change password retry count check.
11. Extract the read_marshal/write_marshal for certtool.h.
12. Remove the old implementation.