Fixed a bug (was possible to create two teams with the same name).
The max size of the name of an internal team is 16 characters.
Fixed this point.

Also, the name of the solo teams are checked and another name is generated in case of duplicata.
The other name is the original, with after a random number.
Changed the way pseudonyms are colorized, to support non-colored teams.
Increased the maximum size of the scoreboard's title to 32 characters.
(I.e. the maximal size defined by Minecraft Vanilla.)