There are 3 sections in there, all useless.
Section 1 tells you how to install Swift packages from the swift-core
PPA. However, the latest version there is ancient.
Section 2 tells you how to build your own Swift packages. However, it
talks about getting the source code from the "debian" branch in bzr,
which is obviously really old.
Section 3 tells you how to take the packages from section 2 and
install them. This isn't too out-of-date, but since section 2 doesn't
work any more, section 3 is useless.
Since stale docs are worse than no docs, there's no current
information in this document, and bringing it up-to-date requires a
whole pile of work, I've chosen to delete it entirely.
Also pulled out a couple references to the PPA elsewhere.
Fixes bug 917385.
Fixes bug 1026145.
Change-Id: I510bd8619531fe110419e5488bd20d3602868d66
bf90ba2de1