TODO

Features
========
- save/load stock data from file
- get stock data (prices, etc) from yahoo or other websites
- recalculate stock rating periodically
- save old stock ratings


# TODO: 
- change argparse to use subcommand e.g:
  "./stockananalyser add [-d <SYM> <URL>]"
  "./stockananalyser show [-v -d]"
- add a refresh function to CLI, recalculates the score of a saved stock and ask
  for the quarterly figure release date if it makes sense
- show rating of all saved stocks in an overview, show the difference between
  the current and the last calculated store (last calculated score should be at
  least X days old, doesn't make sense to show the score that was calculated
  20seconds ago to compare it with the current one)

- allow to show data/scores of all stores stocks
- ask for quarterly release date when showin
- get stock symbol from onvista page
- get quarterly figure release dates from finanzen.net
- allow to store quarterly release date figures of the future
- get current stock quote from onvista page instead of from yahoo
- add CLI:
 - allow to enter new STocks with symbol
 - offer to load stock data if it already exist
   - check which values are outdated and have to be entered again

- check also main.py with pylint

- add support for non-Dax Stocks
- write more tests, ensure functions are also working correctly in corner cases
  (getting quotes on weekend  days, year breaks, etc)
- only ask for stock data that is outdated on the CLI
- Store portfolio
- store objects as JSON instead of using pickle? Would make it easier to
  transist objects to new versions?
- Rename input module, to not clash with the naming of the input() function
- make levermann evaluation threaded to speed it up (YQL queries take lot of
  time)

- todo: verify, do we also need the timezone for the quarterly figures
release date??
# could it happen that when the date for the quarterly figures is in a
# differnt timezone than the stock exchange, that we compare the wrong
# dates?
# is it ensured that the quarterly figures are released during the time the
# exchange is open? or could it be released outside of their opening hours
# and we would have to check the following day instead?