logging clean-up

- moved most constants to separate file
- sorted and cleaned-up imports
- moved logging setup to separate file

cps/cache_buster.py

@@ -17,8 +17,14 @@
 # Inspired by https://github.com/ChrisTM/Flask-CacheBust
 # Uses query strings so CSS font files are found without having to resort to absolute URLs
 
-import hashlib
+from __future__ import division, print_function, unicode_literals
 import os
+import hashlib
+
+from . import logger
+
+
+log = logger.create()
 
 
 def init_cache_busting(app):
@@ -34,7 +40,7 @@ def init_cache_busting(app):
 
     hash_table = {}  # map of file hashes
 
-    app.logger.debug('Computing cache-busting values...')
+    log.debug('Computing cache-busting values...')
     # compute file hashes
     for dirpath, __, filenames in os.walk(static_folder):
         for filename in filenames:
@@ -47,7 +53,7 @@ def init_cache_busting(app):
             file_path = rooted_filename.replace(static_folder, "")
             file_path = file_path.replace("\\", "/")  # Convert Windows path to web path
             hash_table[file_path] = file_hash
-    app.logger.debug('Finished computing cache-busting values')
+    log.debug('Finished computing cache-busting values')
 
     def bust_filename(filename):
         return hash_table.get(filename, "")