pw_tokenizer: Python package

Add the pw_tokenizer Python package, which is used to manage token
databases and decode tokenized strings. pw_tokenizer can be used from
other Python code or from the command line. Three command line utilities
are provided:

  - database.py: Manage tokenized string databases.
  - detokenize.py: Decode and detokenize strings.
  - elf_reader.py: Read data from ELF files by section or address.

Change-Id: I87b19a8f8433a34a254560fc72e5522a74d5a02d
diff --git a/.pylintrc b/.pylintrc
index 00c5853..85cf4fa 100644
--- a/.pylintrc
+++ b/.pylintrc
@@ -296,8 +296,10 @@
 good-names=i,
            j,
            k,
+           db,
            ex,
            fd,
+           ok,
            Run,
            T,
            _