Minor coding style fixes

Don't use TOSERVER_RECEIVED_MEDIA but TOSERVER_CLIENT_READY as indicatio for client ready
Handle clients with protocol version < 23 (almost) same way as before
Make client tell server about it's version
Add client state to not send bogus player position updates prior init complete
Add access to statistics information (peer connction time,rtt,version)
Fix clients standing stalled in world while preloading item visuals (new clients only)
Add get_player_information to read client specific information from lua

  -add client states to avoid server sending data to uninitialized clients
  -don't show uninitialized clients to other players
  -propper client disconnect handling
Minor comment fixes in server
Minor bugfixes in connection
  -improved peer id calculation
  -honor NDEBUG flag
  -improved disconnect handling
  -increased initial send window
Remove some dead code

* If client count is unbearable, immediately delete denied clients
* Re-prioritize the checking order of things about incoming clients
* Remove a huge CPU-wasting exception in ReliablePacketBuffer

Two new configuration options are added:
     - "enable_ipv6" to enable/disable the overall use of IPv6
     - "ipv6_server" to enable/disable the use of IPv6 sockets when running
       a server (when "enable_ipv6" is enabled)

Switch the license to be LGPLv2/later, with small parts still remaining as GPLv2/later, by agreement of major contributors

Make Connection::Receive return the data via a SharedBuffer reference, so the caller doesn't have to choose the right buffer size in advance.

Conflicts:

	src/test.cpp

utility.h: Change Buffer's interface to be more compatible with SharedBuffer's interface, connection.h: use Buffer instead of SharedBuffer in command and event queues

--HG--
rename : src/licensecomment.txt => licensecomment.txt