Added type annotations and use of Path

Replaced some instances of os.path with the Path object from pathlib for
readability. Also added type annotations to MCprepEnv as we're moving
towards that. This also means MCprep will not work at all in Blender
2.7x due to the use of new syntax.

This will be the first in a long process of modernizing MCprep's code
with 2.8 style code. Blender 2.7x users may not be happy, but it's for
the better. If anything, 6 years worth of 2.7x support was a mistake (in
my opinion), as it limited what we could do and opened MCprep to even
more bugs (like in Blender 2.93 with make_annotations, which ironically
now is deprecated).

MCprep_addon/conf.py

@@ -17,7 +17,7 @@
 # ##### END GPL LICENSE BLOCK #####
 
 import os
-
+from pathlib import Path
 import bpy
 
 # check if custom preview icons available
@@ -33,36 +33,27 @@
 
 class MCprepEnv:
 	def __init__(self, dev_build=False, verbose=False):
-		self.dev_build = dev_build
-		self.verbose = verbose
-		self.very_verbose = dev_build
+		self.dev_build: bool = dev_build
+		self.verbose: bool = verbose
+		self.very_verbose: bool = dev_build
 
 		self.data = None
 		self.json_data = None
-		self.json_path = os.path.join(
-						os.path.dirname(__file__),
-						"MCprep_resources",
-						"mcprep_data.json")
-
-		self.json_path_update = os.path.join(
-							os.path.dirname(__file__),
-							"MCprep_resources",
-							"mcprep_data_update.json")
+		self.json_path: Path = Path(os.path.dirname(__file__), "MCprep_resources", "mcprep_data.json")
+		self.json_path_update: Path = Path(os.path.dirname(__file__), "MCprep_resources", "mcprep_data_update.json")
 
 		# if new update file found from install, replace old one with new
-		if os.path.isfile(self.json_path_update):
-			if os.path.isfile(self.json_path) is True:
-				os.remove(self.json_path)
-			os.rename(self.json_path_update, self.json_path)
+		if self.json_path_update.exists():
+			self.json_path_update.replace(self.json_path)
 
 		# lazy load json, ie only load it when needed (util function defined)
 
 		# -----------------------------------------------
 		# For preview icons
 		# -----------------------------------------------
 
-		self.use_icons = True
-		self.preview_collections = {}
+		self.use_icons: bool = True
+		self.preview_collections: dict = {}
 
 		# -----------------------------------------------
 		# For initializing the custom icons
@@ -76,11 +67,11 @@ def __init__(self, dev_build=False, verbose=False):
 		# To ensure shift-A starts drawing sub menus after pressing load all spawns
 		# as without this, if any one of the spawners loads nothing (invalid folder,
 		# no blend files etc), then it would continue to ask to reload spanwers.
-		self.loaded_all_spawners = False
+		self.loaded_all_spawners: bool = False
 
-		self.skin_list = []  # each is: [ basename, path ]
-		self.rig_categories = []  # simple list of directory names
-		self.entity_list = []
+		self.skin_list: list = []  # each is: [ basename, path ]
+		self.rig_categories: list = []  # simple list of directory names
+		self.entity_list: list = []
 
 		# -----------------------------------------------
 		# Matieral sync cahce, to avoid repeat lib reads
@@ -97,16 +88,12 @@ def __init__(self, dev_build=False, verbose=False):
 
 
 	def icons_init(self):
-		# start with custom icons
-		# put into a try statement in case older blender version!
-		global preview_collections
-
 		collection_sets = [
 			"main", "skins", "mobs", "entities", "blocks", "items", "effects", "materials"]
 
 		try:
 			for iconset in collection_sets:
-				preview_collections[iconset] = bpy.utils.previews.new()
+				self.preview_collections[iconset] = bpy.utils.previews.new()
 
 			script_path = bpy.path.abspath(os.path.dirname(__file__))
 			icons_dir = os.path.join(script_path, 'icons')
@@ -156,7 +143,6 @@ def log(self, statement, vv_only=False):
 
 # ! Deprecated as of MCprep 3.4.2
 def init():
-
 	# -----------------------------------------------
 	# Verbose, use as env.verbose
 	# Used to print out extra information, set false with distribution
@@ -349,7 +335,7 @@ def unregister():
 			try:
 				bpy.utils.previews.remove(pcoll)
 			except:
-				log('Issue clearing preview set ' + str(pcoll))
+				env.log('Issue clearing preview set ' + str(pcoll))
 	env.preview_collections.clear()
 
 	env.json_data = None  # actively clearing out json data for next open