Returns 'ok' on success.
+user/available?username=foo&domain=bar
+user/available?user=foo@bar.bz
+ Tests an address to see if it is available.
+
+ Returns 'ok' with 'cause' = 'nonexistant' if the address is available.
+
+ Returns 'failed' with 'cause' = 'exists' if the address is in use.
+
user/gen_pw
Generates a random password on the same form as that used by
user/add_local.
authentication-mechanism :)
-Add collision prevention for users, make sure that no user can be added when the user
-address would overlap/collide with a valid alias-address
-
Change all GET to POST
Implement test-tool for POST-based communication ;)