Add settingtypes.txt to configure player trapping and message logging

There are also some changes to fix problems when trapping is enabled while damage is disabled or the other way round.

nether/settingtypes.txt

@@ -0,0 +1,19 @@
+#    If enabled, regular players which are in the nether can leave it only with
+#    a nether portal and other ways of teleportation, e.g. the /spawn
+#    chatcommand, are blocked. Similarly, the nether can only be entered with a
+#    portal.
+#    This forces the players to investigate the nether and build a portal with
+#    hellish effort to go back to their home in the overworld.
+#    It is recommended to disable this setting in creative mode or if damage is
+#    disabled.
+nether.trap_players (Trap players) bool true
+
+#    If enabled, show log messages in the chat and not only in debug.txt
+nether.log_to_chat (Log messages to chat) bool false
+
+#    Specify how much text is printed for debugging purposes
+#    0: Disabled
+#    1: A bit of information
+#    2: Acceptable amount of information
+#    3: Lots of text
+nether.log_level (Log level) int 2 0 3