* trainerbattle_normal → trainerbattle_single * TRAINER_BATTLE_NORMAL → TRAINER_BATTLE_SINGLE * improves the macro documentation a little
* adds battle type macros * adds `trainerbattle_normal` macro * adds `trainerbattle_double` macro * adds rematch macros * adds no intro macro
* adds some constants for standard script names and messagebox types * replaces some callstd calls with msgbox calls where equivalent * replaces msgbox and callstd calls using raw digits with versions that use the constants