Add checks for invalid user input for important settings
Rename Settings::tryGet* to Settings::get*NoEx for consistency

This reverts commit 3f376a09.

Rename try* non exceptioning functions to *NoEx

MapgenParams is no longer a polymorphic class, eliminating the need for messy and bug-prone reallocations.
Separation between the common and mapgen-specific parameters is now strongly defined.
Mapgen parameters objects are now properly encapsulated within the proper subsystems.

  -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

As suggested by qwrwed.

Fixed lua error when none of the worlds or servers selected are and connect,
delete or configure buttons used.

Fixes camera glitch and cheating at drowning