game_restart() throws an error

[JujuAdams]

Scribble actively prevents the user from reinitialising the library as this causes a ton of issues. This causes issues when someone wants to use game_restart(), however.

...not sure why people are using game_restart() but here we are.

SCRIBBLE_WARNING_REINITIALIZE should be added as a macro to control whether a warning is shown when trying to reinitialize Scribble. Additionally, scribble_init() should return whether the library was initialized successfully. This allows the following design pattern:

if (scribble_init(...))
{
    //Initialized for the first time, define things that we need
    scribble_add_spritefont(...);
    scribble_add_font(...);
    scribble_add_color(...);
    scribble_autotype_add_event(...);
}