feat: several improvements to azlux's token auth scheme #154

1. 'auth_method' in config, where users can select between
   'password' and 'token'.
2. create index for token, avoid iterating the entire user
   section when validating tokens.
3. only generate token for a user when there's no token for
   him in the db, avoid tokens fill the db.

configuration.example.ini

@@ -108,33 +108,35 @@ port = 64738
 #     - "pause",
 #     - "pause_resume" (pause and resume once somebody re-enters the channel)
 #     - "stop" (also clears playlist)
-#     - "nothing" or leave empty (do nothing)
-#when_nobody_in_channel = nothing
+#     - leave empty (do nothing)
+#when_nobody_in_channel =
 
 # [webinterface] stores settings related to the web interface.
 [webinterface]
 # 'enable': Set 'enabled' to True if you'd like to use the web interface to manage
 #     your playlist, upload files, etc.
 #     The web interface is disable by default for security and performance reason.
+# 'access_address': Used when user are questing the address to access the web interface.
 #enabled = False
 #listening_addr = 127.0.0.1
 #listening_port = 8181
 #is_web_proxified = True
+#access_address = http://127.0.0.1:8181
 
 # 'web_logfile': write access logs of the web server into this file.
 #web_logfile =
 
-# 'required_auth': Set this to True to enable password protection for the web interface.
-#require_auth = False
-#user =
-#password =
+# 'auth_method': Method used to authenticate users accessing the web interface.
+#                Options are 'password', 'token', 'none'
+#auth_method = password
 
-# Set this option to match mumble user with user on the webinterface
-# It's working with an unique token an user can ask to the bot with token and to add music to the bot.
-# It's also allow users to know who have add a music from the webinterface
-# match_mumble_user = True
+# 'user', 'password': If auth_method set to 'password', you need to set the username and
+#                     password.
+#user = botamusique
+#password = mumble
 
-# To use token (need session) flask need a password to encrypt/sign cookies used. !! YOU NEED TO CHANGE IT IF PREVIOUS OPTION IS TRUE!! 
+# 'flask_secret': To use token, flask need a password to encrypt/sign cookies.
+#                 !! YOU NEED TO CHANGE IT IF auth_method IS 'token'!!
 # flask_secret = ChangeThisPassword
 
 # [debug] stores some debug settings.