Allow mutators to hook into the CUSTOM_HOME gamemode

[cooba]

[21:37:10] PJ CC: a future jj2+ edition should have support for a
[21:37:27] PJ CC: generic custom mode
[21:37:37] PJ CC: designed to be used with mutator custom modes
[21:37:46] cooba[si]: this already exists in a way
[21:37:58] cooba[si]: but should be expanded into what you're saying more or less

[Violet CLM]

My vision of how this would work looks something like this:

In some script module:
class DoubleDom : jjCUSTOMGAMEMODE {
//various methods go here
}

And then command:
/gamemode DoubleDom

which instantiates a member of that class and runs its constructor default or otherwise.

Ideally there would be enough methods and things for any of the native gamemodes to be fully replicable in the script, but I definitely haven't taken the time to think through what all that would require.