Lordown should ignore LORCODE markup

Content of the following tags should remain unprocessed:

• url
• inline
• code
• user

Rest tags should be treated literarily:

• s (e6be32c4)
• u (e6be32c4)
• b (e6be32c4)
• i (e6be32c4)
• u (e6be32c4)
• em (e6be32c4)
• strong (e6be32c4)
• list (e18f3c20)
• quote (e18f3c20)
• cut (e18f3c20)
• pre
• [*] (98462be6)
• [[tag]] (escaped tag)