additional log

Retract tags taken by mistake from kiwicom/gocql

Retract v1.8.0, v1.8.1, v1.9.0, v1.10.0 - tags mistakenly taken from
kiwicom/gocql, which are not actual releases made in scylladb/gocql.

Even though those tags were removed from scylladb/gocql (see scylladb#110),
some Go module mirrors have already fetched them:

  $ go list -m --versions github.com/scylladb/gocql
  github.com/scylladb/gocql v1.0.0 v1.0.1 v1.0.2 v1.0.3 v1.0.4 v1.1.0 v1.2.0 v1.2.1 v1.3.0-rc.1 v1.3.0 v1.3.1 v1.3.2 v1.3.3 v1.3.4 v1.4.0 v1.4.1 v1.4.2 v1.4.3 v1.5.0 v1.6.0 v1.7.0 v1.7.1 v1.7.2 v1.7.3 v1.8.0 v1.8.1 v1.9.0 v1.10.0

As we can't control those mirrors, they will always return an incorrect
version of gocql, even if we release "new" 1.9.0, 1.10.0.

Subsequent to merging of this patch, version v1.11.0 of scylladb/gocql
will be released.

Merge remote-tracking branch 'gocql/master'

Add configurable MaxRequestsPerConn cluster param

Before this change, a connection had a hardcoded maximum number of
streams. Since this value was so large (32768 for CQL v3+) this
essentially meant an unbound concurrency.

This commit allows a user to configure this parameter by a newly
added MaxRequestsPerConn option.

The "MaxRequestsPerConn" naming was chosen to be very general
deliberately to allow us to safely introduce a more advanced behavior in
the future: where the concurrency limiting happens not at a IDGenerator
level and an additional client-side queue is introduced for requests
to wait to be sent to Scylla (in addition to inflight requests).

This commit deliberately does not change the defaults as to be
non-pessimizing for the users.

Fixes scylladb#112

Merge pull request scylladb#103 from kiwicom/ms/scylla-dialer-cleanup

Remove scyllaConnPicker.dialer