[PATCH] devel/bison: update to 2.0, take maintainership

[Björn König]

Hello,

You can't update devel/bison, because too many ports depends on bison 
1.75. Since 2.0 is not backward compatible to 1.75 this would break a 
loooot of ports. Even for this reason devel/bison was not updated to 
1.8x, but rather a new port was created: devel/bison1875. A new port for 
bison 2.x would be better, e.g. devel/bison20.

Regards Björn