Added in DB read and write functions.

Written offline, so requires some level of testing.

Testing method for writing:
````
lua_run Adb = {}
lua_run Adb[1234567] = {name="MrTesty", health=100, strength=10, banana="tasty"}
lua_run WriteTableToID(1234567)
````
WriteTableToID should return true if it succeeded, the contents of "arpg/db/id/1234567.txt" should now contain:
````
Adb[1234567] = {
    name = "MrTesty",
    health = 100,
    strength = 10,
    banana = "tasty"
}
````

Testing method for reading (after if file has been created by write):
````
lua_run Adb = {}
lua_run ReadIDToAdb(1234567)
lua_run PrintTable(Adb[1234567])
````
ReadIDToAdb should return true after succeeding, and PrintTable should print the expected contents of Adb.