Persistence Patch

- Fixes Paper and font tags stacking across rounds, as shown in: ![](https://cdn.discordapp.com/attachments/187013248309002240/741937939382141000/164fdd3a37fb22f18dfa9b5c431ffc04.png)

- Fixes Graffiti being persistent for over 50 rounds (10+ days)
- Sets Trash to be persistent for 4 rounds instead of 5
- Fixes Persistence being always-on because of if("persistence_enabled") config.persistence_enabled = 1. As explained: 
> it's on by default, which means config.txt will be read and if it's not there it stays at 1. If it is there,it gets set to 1. There is no way to disable it

- Adds config options to enable/disable **Persistence for Maploaded objects**, as well as a verb to toggle such.
- Adds Persistence to config.

Currently IGNORE_MAPLOAD for Persistance is **Disabled.**
Maploaded objects/dirt/etc will be saved by persistence, preserving current behavior.

code/modules/persistence/datum/persistence_datum.dm

@@ -6,8 +6,8 @@
 	var/name
 	var/filename
 	var/tokens_per_line
-	var/entries_expire_at
-	var/entries_decay_at
+	var/entries_expire_at						// Set in rounds, this controls when the item is finally removed permanently regardless if cleaned or not.
+	var/entries_decay_at						// Set in rounds. This controls when item messages start getting scrambled.
 	var/entry_decay_weight = 0.5
 	var/file_entry_split_character = "\t"
 	var/file_entry_substitute_character = " "