The first commit for this its https://github.com/mangos/one/commit/8cd46197e1efbb34fc1a5be27a7cdace3f57de98, table world_template for calling script in ScriptDev2 whith map id when is loaded and table world in characters database for save some data string.
Wintergasp can be added whth this function.
Very simple example:
If you would say something when the player enter on the map, you just make a script and respect ScriptDev2 structure : (reset(),update(),etc.. and insert in the table world_template this name and id example : (say_welcome_xx,xxx), they are few script example in the ScriptDev2 source and the ScriptDev2 forum can help you too.
For outdoor pvp script is not very hard because you already have the script for each map, you need adapt this into ScriptDev2 but there is always a small part of code like flags outdoor pvp structure that you need insert in mangos.
More proper code, less hacky code, have nice .