Fix ESL activation with 254 mods RRR

Was trying to activate the ESL's masters, even when they were already
enabled. This normally fails two lines down, at the 'fileName not in
self._active_wip' check, but not if you have 254 masters, where it
causes a 'too many masters' warning first. We now check if the masters
haven't already been enabled before trying to activate them. May make
mod activation a bit faster as well - also went ahead and sped up the
active_wip lookup by making a set for it, since lookup occurs for each
master and can potentially take O(m*n) time, where m = #masters and
n = #LO mods. Now takes at most O(m) time.

This could potentially have affected load orders for the older games as
well, but I haven't tested it yet.

Under # 309 <--- RRR

Author: Infernio

Mopy/bash/bosh/__init__.py

@@ -2313,11 +2313,15 @@ def lo_activate(self, fileName, doSave=True, _modSet=None, _children=None,
             #  Disabled for now
             ##if self[fileName].hasBadMasterNames():
             ##    return
+            # Speed up lookups, since they occur for the plugin and all masters
+            acti_set = set(self._active_wip)
             for master in self[fileName].get_masters():
-                if master in _modSet: self.lo_activate(master, False, _modSet,
-                                                       _children, _activated)
+                # Check that the master is on disk and not already activated
+                if master in _modSet and master not in acti_set:
+                    self.lo_activate(master, False, _modSet, _children,
+                                     _activated)
             #--Select in plugins
-            if fileName not in self._active_wip:
+            if fileName not in acti_set:
                 self._active_wip.append(fileName)
                 _activated.add(fileName)
             return load_order.get_ordered(_activated or [])