Issue #1728 Request Queue Size via REST

This allows the size of a distributed queue to be returned via the REST
API.
Add tests for queue size rest API.
Allow RequestWrapper.RequestDispatcher to use the provided servletRequest

Currently, the RequestDispatcher that's returned by RequestWrapper always passes
the RequestWrapper to the wrapped RequestDispatcher instead of the request that
was provided to the forward or include method. This prevents a caller from
providing a wrapper of its own; the provided wrapper is ignored by the
RequestDispatcher.

The current behaviour is presumably a defensive move to prevent callers from
passing in the unwrapped request and thereby 'escaping' the wrapper that
provides the distributed HttpSession. There is no need for this because:

* if the caller has access to the unwrapped request, he can already break
  the distributed HttpSession
* if the caller does not have access to the unwrapped request, he can't
  break the distributed HttpSession either.
* Disabled backup operation scheduling, not needed since backup replicas are synced by partition updates.
* Fixed backup replica version calculation during backup op send.
* Fixed backup replica index calculation.
* Limited parallel replica sync operations.
* Removed problematic test marker from BackupTests.
checkstyle fixes
Fixes #1949. Introduced TraceableOperation interface for operations those off-load their execution and terminate, like executor service operations.
Merged with latest master bracnh
Merged with latest master bracnh
Merge pull request #1809 from drewrm/issue_1728

Issue #1728 Request Queue Size via REST
Merge pull request #1994 from mdogan/fix/3.2/partition

PartitionService backup/replication fixes...
Merge pull request #1995 from mdogan/fix/3.2/issue-1949

Fixes #1949. Introduced TraceableOperation interface for operations thos...
Fixed compilation issue -> RestTest imports
Improved `testPutWithTtl`; ttl should be bigger than 5sec (= sync backup wait timeout)
exception handling improvement
Merge pull request #1981 from mheemskerk/fix/wm/request-dispatcher

Allow RequestWrapper.RequestDispatcher to use the provided servletRequest
Merge pull request #2017 from mdogan/fix/3.2/basic-map-test

Improved `testPutWithTtl`
Merge pull request #2018 from ahmetmircik/minorExceptionHandlingImprovement

Exception handling minor improvement
Ignored ConnectionTest completely.
move slow tests into nightly-build profile
Merge remote-tracking branch 'origin/master'