Fixed a bug related to the freezer
If a player is frozen twice, he is unfrozen the second time.

Also, minor code cleanups.
Moved code from the main class to related subclass.

Import of the teams from the config: moved to the UHTeamManager class.
Import of the spawn points from the config: moved to the UHGameManager class.
Misc code cleanups.
Improved help pages
 - Space separator if the sender is a player;
 - added title to locate the beginning of the help;
 - fixed some forgotten arguments with spaces.
Added /uh about command to display infos about the plugin & the translation.

Also, reorganized commands in the help.
Fixed a bug (startup crash if the language is unknown).
Added license texts in all java files.
Added license in /uh about
Improved help pages.
Improved the safe spot finder.
(Water is an acceptable floor, to avoid a teleportation in the floor of the oceans.)
Improved I18n manager.
 - The only languages kept in memory are the current and fallback ones.
 - Bugfixes.