Add suite for testing secure connections to the server

The tests make sure that clients that want to use SSL 3.0 will be rejected
and those using TLS (1.0, 1.1, 1.2) will be accepted.
Use customized escalus from the branch

NOTE: This commit is not intended to be merged!
Merge pull request #84 from esl/secured_connections

Add suite for testing secure connections to the server
use specific commit from escalus
Add first tests for live configuration reload mechanism

These commit introduces tests that cover basic cases of configuration
reload related to changing XMPP domain.

Currently all the work on configuration reload is kept in
https://github.com/esl/MongooseIM/tree/conf-reload
Use nullary reload_local command

(cherry picked from commit 2c2671c823afe39ad4ec8ab17ac6c32307702d3a)
Make the tests run independently

(cherry picked from commit 1af297cd47af78a9efe151ac191638c7d496ecff)
Print and log external command errors

(cherry picked from commit c379b166ded1d8b8a3161a816479913ee2ac3b4a)
Cleanup spurious whitespace

(cherry picked from commit f16e63e06589c65d6a1bd4be5150df8b662f9050)
Include conf_reload suite in specs
Merge pull request #86 from esl/conf-reload

Tests for configuration reload
use all tests suites (sort them alphabetically)
define common and generic item counters

to be used from tests (as an example offline count from sm_SUITE)
check server purity after suite

print warning message if the state is not clean
use escalus from branch travis-full-spec
clean last_activity after anon user

this should be cleaned by anonymous_purge_hook
but after this hook there is unset_presence_hook run
which sets the last_activity info back...
manually clean last_activity after user connected over BOSH
check carboncopy purity
check registered users count after suite
lowercase username before setting last info manually