Rename os_agnostic.py to the more appropiate os_specifics

to encapsulate file system unique filename and path handling

apps/document_indexing/os_specifics.py

@@ -3,7 +3,7 @@ import os
 from document_indexing.conf.settings import SUFFIX_SEPARATOR
 
 
-def assemble_document_filename(filename, suffix=0):
+def assemble_suffixed_filename(filename, suffix=0):
     '''
     Split document filename, to attach suffix to the name part then
     re attacht the extension
@@ -14,3 +14,7 @@ def assemble_document_filename(filename, suffix=0):
         return SUFFIX_SEPARATOR.join([name, unicode(suffix), os.extsep, extension])
     else:
         return file_filename
+
+
+def assemble_path_from_list(directory_list):
+    return os.sep.join(directory_list)