Improve and expand model hash exclusions

Squashed commit consisting of these 3 commits:

1. Drop MelModelHash in favor of MelNull

MelNull already does what we want - the definitions are almost
identical! The only real difference is that MelModelHash also saves the
texture hashes as an attribute of the record. This is obviously totally
unnecessary - we don't want to do anything with those hashes.

To that end, let's just drop those classes and use MelNull.

2. [SSE] Drop PROJ/NAM2 and BPDT/NAM5

These are texture hashes as well! zilav pointed this out [1], but it
looks like this got missed when the texture hash changes were originally
made. I don't know if WB actually patches or writes these, but better
safe than sorry.

[1] wrye-bash#403 (comment).

3. Correct texture hash explanation - TO BE SQUASHED

The actual explanation, as provided by zilav, is that texture hashes are
just an optimization and are totally optional - plenty of records in
Skyrim.esm don't have them.

Author: Infernio

Mopy/bash/game/fallout4/records.py

@@ -40,21 +40,14 @@ class _MelModel(MelGroup):
                     # Destructible
                     'DMDL': ('DMDL', 'DMDT', 'DMDC', 'DMDS'), }
 
-        class MelModelHash(MelBase):
-            """See game.skyrim.records._MelModel.MelModelHash"""
-            def loadData(self, record, ins, sub_type, size_, readId):
-                MelBase.loadData(self, record, ins, sub_type, size_, readId)
-            def getSlotsUsed(self):
-                return ()
-            def setDefault(self,record): return
-            def dumpData(self,record,out): return
-
         def __init__(self, attr='model', subType='MODL'):
             """Initialize."""
             types = self.__class__.typeSets[subType]
             MelGroup.__init__(
                 self, attr, MelString(types[0], 'modPath'),
-                self.MelModelHash(types[1], 'textureHashes'),
+                # Ignore texture hashes - they're only an optimization, plenty
+                # of records in Skyrim.esm are missing them
+                MelNull(types[1]),
                 MelOptStruct(types[2], 'f', 'colorRemappingIndex'),
                 MelOptStruct(types[3], 'I', (FID,'materialSwap')),
                 MelBase(types[3], 'modf_p'),

Mopy/bash/game/skyrim/records.py

@@ -50,22 +50,14 @@ class _MelModel(brec.MelGroup):
                     'MOD5': ('MOD5', 'MO5T', 'MO5S'),
                     'DMDL': ('DMDL', 'DMDT', 'DMDS'), }
 
-        class MelModelHash(MelBase):
-            """TextureHashes are not used for loose files and there is never a
-            Bashed Patch.bsa. So we read the record if present and then
-            discard it."""
-            def loadData(self, record, ins, sub_type, size_, readId):
-                MelBase.loadData(self, record, ins, sub_type, size_, readId)
-            def getSlotsUsed(self):
-                return ()
-            def setDefault(self, record): return
-            def dumpData(self, record, out): return
-
         def __init__(self, attr='model', subType='MODL'):
             """Initialize."""
             types = self.__class__.typeSets[subType]
             MelGroup.__init__(self, attr, MelString(types[0], 'modPath'),
-                              self.MelModelHash(types[1], 'textureHashes'),
+                              # Ignore texture hashes - they're only an
+                              # optimization, plenty of records in Skyrim.esm
+                              # are missing them
+                              MelNull(types[1]),
                               MelMODS(types[2], 'alternateTextures'), )
 
         def debug(self, on=True):
@@ -1637,7 +1629,9 @@ def loadData(self, record, ins, sub_type, size_, readId):
                       'limbReplacementScale'),
             MelString('NAM1','limbReplacementModel'),
             MelString('NAM4','goreEffectsTargetBone'),
-            MelBase('NAM5','textureFilesHashes'),
+            # Ignore texture hashes - they're only an optimization, plenty of
+            # records in Skyrim.esm are missing them
+            MelNull('NAM5'),
             ),
         )
     __slots__ = melSet.getSlotsUsed()
@@ -5050,7 +5044,9 @@ def loadData(self, record, ins, sub_type, size_, readId):
                   ),
         MelGroup('models',
             MelString('NAM1','muzzleFlashPath'),
-            MelBase('NAM2','nam2_p'),
+            # Ignore texture hashes - they're only an optimization, plenty of
+            # records in Skyrim.esm are missing them
+            MelNull('NAM2'),
         ),
         MelStruct('VNAM','I','soundLevel',),
         )