Build environment compatible with Wheezy

Originally created by @intrigeri on #7217 (Redmine)

live-build 2.x is a pain to install on Wheezy and later, so we have to find a solution to that (be it migrating to live-build 3.x, or to something else). For Tails 1.1, we’ll go with live-build 2.x, using a custom package thereof, with a version greater than Wheezy’s 3.x.

Related issues

Copied from #5691 (closed)

Edited May 15, 2020 by intrigeri

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