LICENSE: Make things LibreJS friendly
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 firstname.lastname@example.org