templates/base-page: Added optional title_right block
templates/flights: Added "IGC" download button to the title section

.. and removed download link from the details table
README: Updated TravisCI link and image URL
README: Updated Github URLs
README: Updated "Contributing" content
Merge pull request #12 from Turbo87/readme-update

README updates
Merge pull request #13 from Turbo87/igc-button

Added IGC download button