Grab flights only if they are stored under the given confirmation code; ignore any other reservations

The page we are parsing may include not just flights with the given confirmation number, but also 'associated products' with different confirmation numbers. Prior to this fix, ReservationInfoParser pulled all of the flights, regardless of confirmation number. Because of this, the program sent an e-mail promising to check in to all associated flights, but was only able to check in to the flights with the given confirmation number.

This commit fixes the bug by ensuring that ReservationInfoParser only pulls flights for the given confirmation number.

At some point, we could add a feature, giving the user the option to check into all 'associated' flights. This should be easy. The 'associated products' (flights with differing confirmation numbers) are located inside the tag <h3 class="trip_associated_products">.
added ATL
updated readme to reflect new application settings

- closes #14
additional timezones
Update README.md

Add required libraries to installation instructions.
dd# Untracked files:
Updated time zones and email debugs
Update README.md

Corrected spelling
PS on line 50 - there is not a spot to edit the email and password in sw_checkin_email.py. SHould that be edit default_settings.py ?
Update README.md

Moved install notes for Ubuntu 12 to bottom
Added note about Gmail two factor auth.
Merge pull request #18 from dcjones21/master

Time Zone Update for international
fixes #19
readme clarification
send email if either config email option is set
Added MAX_RETRIES parameter.

When CHECKIN_WINDOW=0, the program gives up too early. Fixed this by adding a
MAX_RETRIES parameter instead.
send_email now uses EMAIL_TO config instead of throwing exception if email param not passed.
Applied patch from SarahPythonista to grab flights only if they are stored under the given confirmation code
Added KNOWN ISSUES to README with DB bug workaround
Merge pull request #8 from SarahPythonista/master

Grab flights only if they are stored under the given confirmation code; ignore any other reservations
merged pr #23
readme update