Merge pull request eBay#96 from szmyd/integrate_grpc_library

Integrate grpc library

improve logging (eBay#88)

Co-authored-by: Ravi Akella email = [email protected] <raakella@sdsbuild07>

Cherrypick fixes (eBay#83)

* resolve deadlock in file watcher on_modified_event

* improve unit test

* resolve the bug in multiple listeners case in file watcher

* ad manual token parser

* bump conan version

Co-authored-by: Ravi Akella email = [email protected] <raakella@sdsbuild07>

Merge pull request eBay#69 from szmyd/libc_no_prerelease

Change all libc builds to PRERELEASE=False

SDSTOR-5593 Fix for metrics remain exposed after volume is deleted. (e…

…Bay#164)

Fundemental problem is metrics uses prometheus labels to register and
when the volume is deleted, metrics actually deregisters itself.
However, it does not remove the label from prometheus version of metric
family. Hence it continues to emit the metric during prometheus scraping
even though there is no change or update to that metric. Fix is to
actually remove the label corresponding to the volume. This version of
prometheus, however does not allow Unregister of the metric family
itself.

After fixing this, the singleton destruction order has changed, result
in crashes when application starts to use it. This was fixed in develop
branch and some of the fixes are backported.