Expose most common QueuePoll parameters from SQLAlchemy

Fixes bug 1160442

The defualt parameters are used unless otherwise configured. This
is applicable for:
 - pool_size
 - max_overflow
 - pool_timeout

By increasing the pool_size and the max_overflow and lowering the timeout
the issue reported in the bug is resolved.

NOTE: the configuration values enable the user to make use of the default
QueuePool tuning values.

Change-Id: Ic258442531a2caf2db4f05c4ddd6fbfb0c180f17
Fix and enable H90x tests

Only triggering in few places that are easy
to fix. Start gating on those checks.

Change-Id: Ib4ff23159bd83fd3455b5357d5338fe37ca23fa2
Hide lock_prefix argument using synchronized_with_prefix()

The lockfile module has a new convenience API which sets the lockfile prefix.
Using this API, the prefix is not required everytime synchronized is used.
This enables for projects to have consistant prefixes on their lockfiles

Change-Id: I4bc3f28a9ed2a6e2438a90f163bbde081211062c
Imported Translations from Transifex

Change-Id: I076ac10aa31a43369a100acfe72b6737a53c26ee
Merge "Fix and enable H90x tests"
Merge "Hide lock_prefix argument using synchronized_with_prefix()"
Merge "Expose most common QueuePoll parameters from SQLAlchemy"