[wallclock] non-blocking mce call in ctor

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
[wallclock] non-blocking timed call

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
Merge pull request #8 from nemomobile/async-mce-call

[wallclock] non-blocking mce and timed calls in ctor