Adds chrome module for searching history.

- Restructures unit tests
- Shifts to nose for unit testing
- Adds a sample history file with 6 entries to search against as well
Gets Chrome module to a working state

- Shifts to using /tmp/hackertray.chrome for no conflicts
Avoid import pygtk etc
Allow missing pygtk, gtk, webbrowser modules
Detects travis and ignores pygtk
Don't try to import Appindicator on TRAVIS.
Updates testing script
Catches distribution errors for travis
Integrates --chrome option into hackertray main module

- Specify a chrome profile path via --chrome and it takes care of the rest
- The native json db implementation is still used as backup
- Chrome module now uses absolute path of History file
Updates readme for chrome branch
Adds development instructions

- Also adds Chrome Profile path info.
chrome_data_directory was being ignored on next auto refresh
Handles manual refresh for chrome
Adds credits
Implements network error checking in.
Checks for existence of Chrome's History file.
Merge branch 'handle-network-errors'
Updates readme after chrome merge