Database logging
* General
  -- This introduces basic support for sqlite3, and logging specific
  things into a local database.  This is the beginning of the web
  application frontend to zarp, and will continue to expand.  More about
  this on the zarp wiki page.
* config/zarp.conf
  -- Basic configuration file that is read at launch and stuck into a
  database.
* src/core/config.py
  -- Added in a configuration file parser
  -- Added in another set of configuration options that are not
  displayed to the user; this includes, for now, database options
  -- Correctly eval integers
* src/core/module.py
  -- All log_msg calls are now stored in the connected database
  -- Added several database helpers so modules dont need to worry about
  including anything else
* src/core/util.py
  -- Added a timestamp function for generating formatted timestamps
  -- Added a get_calling_mod function that inspects a function's call
  stack to retrieve the name of the calling function.  Useful for
  logging who called log_msg.
* src/modules/scanner/net_map.py
  -- Log scanned hosts to the database
* src/modules/scanner/passive_scan.py
  -- Highlights how easy it is to plug in database logging; logs all
  scanned hosts to the database
* src/modules/sniffer/password_sniffer.py
  -- Logs credentials to database
* zarp.py
  -- Added in a check to verify the python version
  -- Database is now initialized at launch