Metacat

Adding more constant strings.

Chane a info for output.

Change some hard code to constant string.

Change the code to handle permission checking.

Move the permission checking part.

Add a file to handle permission checking.

Get rid of the permission code to handle ticket count and duration.

Add code to delete the previous permission when update.

Now, eml parser can support pulling out access control for document level and subtree level.

Add code to handle subtree.