This adds some source files, a script and skeleton for building
a Debian package that installs the zcash daemon and CLI tool.
Also removes unused Bitcoin files.
This will retry upon refused connections and similar errors, wait 1 second
before the next retry, time out after 10 seconds if no data is received or
the connection times out, plus try an infinite number of times.
Per NCC-2016-017, wget was run with --no-check-certificate,
which means that the connection can be man-in-the-middled,
even if we are verifying the integrity of the params later via hash sums.
The rationale cited in the Bash comments does not stand up to scrutiny.
There's really no persuasive reason not to verify certificates.
Fixes#1346.
Two instances of the fetch-params.sh script running at once will
result in corruption of the proving key and an error when the
hashes are computed. This implements a lock to stop such a
scenario from occurring.
We also terminate and don't create the symlinks if the downloaded
parameters fail the checksum command.
Officialness is determined by a regular expression. ;-)
This is handy because we often want upstream Bitcoin tags for local
diffs, but sometimes we accidentally upload them to github which then
claims they are our releases, which is confusing and misleading.
Kevin Gallagher