GitLab

This commit does a few things in order to make #srctweb work correctly
with LibreJS users.

- Adds a librejs page which includes a table of the external sources we
  used, their licenses, as well as a link to the uncompressed source
  files.

- Adds the uncompressed source of Bootstrap.js v3.0.3

- Adds a link in the footer to the LibreJS page so that the addon can
  find the license table from any page.
Signed-off-by: Mark Stenglein <mark@stengle.in>