Versioned JS files & centralized licenses

[pikzen]

Fixes #96. Tested and haven't noticed any problem on the pages using jquery, qrcode is still fine.

Note: Not using jQuery 2.x is a voluntary choice. There are major API differences, and from what I tested it broke jquery-lazyload.

[nodiscc]

Thanks;
Please move the license/copyright information to https://github.com/shaarli/Shaarli/blob/master/COPYING:

Files: Files: inc/jquery*js, inc/jquery-ui*js
License: MIT License (http://opensource.org/licenses/MIT)
Copyright: (C) jQuery Foundation and other contributors,https://jquery.com/download/

Files: inc/jquery-lazyload*.js
License: MIT License (http://opensource.org/licenses/MIT)
Copyright: (C) Mika Tuupola, https://github.com/tuupola

------------------------------------
The MIT License (MIT)

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

Please also add a link for the qr.js source:
Copyright (C) 2014 Alasdair Mercer, http://neocotic.com, https://github.com/neocotic/qr.js

[pikzen]

Done. Also updated the list of contributors.

[nodiscc]

Great werk, thanks. Is this tested? (my dev laptop is borked right now)

[nodiscc]

After discussing it on the debian mailing list thread, we should also include the unminifed sources in inc/. This takes care of all license compliance problems, and provides a safeguard if the upstream source becomes unavailable in the future.

[pikzen]

Unminified sources added.

[nodiscc]

Thanks @pikzen