flight.js: Fixed bug in barogram elevation handling

The elevation was displayed correctly, but the data source used for the
fix-table was bugged from the beginning...
Merge pull request #109 from Turbo87/barogram

flight.js: Fixed bug in barogram elevation handling
Merge pull request #110 from Turbo87/notifications

Show read notifications too
i18n: Updated Hungarian translation
i18n: Updated Polish translation
i18n: Extracted new messages
i18n: Updated German translation
Merge pull request #111 from Turbo87/i18n

Updated translations
i18n: Fixed format string errors
test_i18n: Use babel library instead of polib

We already have the babel library that can read po files and it is
also directly able to check them for errors so we don't have to do it
ourselves...

One less dependency :)
Merge pull request #112 from Turbo87/i18n

Use babel library instead of polib for unit testing
model/notification: Added user column to events table
notifications-table: Implemented "A is following B now." events

These are no longer restricted to show "A is following you now."
views: Mark flight/user notifications as read if related page is requested
views/notifications: Inject count_unread_notifications() into template

Defer the notification counting until the template is processed to
allow notification update processes to run before. This way if you visit
a user/flight page any notifications for that page will be marked as read
*before* the unread notifications are counted.
notifications-table: Link usernames to their profiles
notifications-table: Show subevents as smaller listing
notifications-table: Show small unread badges for subevents too
notifications-table: Translate "Show" button caption
notifications-table: Adjusted styling