core.open_url(url)
^ opens the URL in a web browser, returns false on failure.
^ Must begin with http:// or https://
+core.open_dir(path)
+^ opens the path in the system file browser/explorer, returns false on failure.
+^ Must be an existing directory.
core.get_version() (possible in async calls)
^ returns current core version
+
Filesystem
----------
Content - an installed mod, modpack, game, or texture pack (txt)
Package - content which is downloadable from the content db, may or may not be installed.
+* core.get_user_path() (possible in async calls)
+ * returns path to global user data,
+ the directory that contains user-provided mods, worlds, games, and texture packs.
* core.get_modpath() (possible in async calls)
* returns path to global modpath
* core.get_clientmodpath() (possible in async calls)