updated configuration & membership update doc files

See merge request !2

fix git clone link in INSTALLATION page so instructions can be copied directly

See merge request !1

:(

There's still an issue to fix in koji, enabling SCL
for that tag.

The parser does not like bash comments, it seems. :P

One more attempt - this time it should build on CC7, as we're
using a more recent compiler now.

Fixes EOS-2443.

That version of gcc appears to be crashing when compiling
the latest version rocksdb, not sure why.. Maybe devtoolset-6
gcc can cope.

Fixes rare assertion errors in "Raft_e2e.replication_with_trimmed_journal"
test.

ZSTD for the bottom compaction level (slower, but achieves a
high compression ratio), LZ4 everywhere else.

This reverts commit 8492af76.

Looks like the default one is running out of memory..

Runs way too quickly now :P

Massive improvement in write performance, reaching 60kHz with
Raft