Use unminified javascript files

    In Debian, minified javascript are considered either as an
obfuscation of the original code, or as a "compiled-in binary"
version of them, and therefore minified javascript files are
considered non-free.

    Moreover, the use of unminified javascript will ease the
development on client side. There will be no impact on Horizon
performance due to the compress tag of Django.

Change-Id: I8f6eee651fe1096cc7262ef92d614c716d2e9b55
backport: havana
Closes-Bug: #1269727
Merge "Use unminified javascript files"