Upgraded flask, werkzeug and Flask-Login packages
templates/about: Use btn-group for social buttons
Add Flask-DebugToolbar extension

This extension works quite a bit better than injecting get_debug_queries()
ourselves and gives even more information than that.
config/testing: Make sure redirects are not intercepted
lib/decorators: Cast self.msg to unicode before flashing

Usually lazy i18n strings are used in self.msg and the JSON module now
complains that those are not serializable.
config: Make DEBUG_TB_INTERCEPT_REDIRECTS = False the default
scripts/copy_flight_py: add script to copy igc files by some criteria
scripts/delete_flight_by: add script to delete flights by some criteria
i18n: Updated Dutch translation
i18n: Updated Finnish translation
i18n: Updated Polish translation
i18n: Updated Russian translation
i18n: Updated French translation
Merge pull request #102 from Turbo87/i18n

Updated translations from launchpad
import_srtm: Use preprocessed TIF files from the download server
Merge pull request #96 from Turbo87/btn-group

templates/about: Use btn-group for social buttons
Merge pull request #103 from Turbo87/srtm

import_srtm: Use preprocessed TIF files from the download server
Merge pull request #94 from Turbo87/debug-toolbar

Add Flask-DebugToolbar extension
Merge branch 'master' into flask-upgrade
test_authentication: Fixed login state tests