Task #10813: Improved reconnect to RADB mechanism in _executeQuery() such that self.cursor.execute(query, qargs) is always called from within a try-statement

Task #10811: radb.py: use db table resource_monitoring.resource_usage for method getResourceUsages. adapted code using getResourceUsages.

Task #10811: added argument where_task_ids to updateResourceClaims method, so we can update all claims for one or more task(s) in one call

Task #10811: added option to get claimable_capacity in method getResources. fixed get_max_resource_usage_between. added little bit of test code to setup some test tasks and claims for demo

Task #10811: intermediate commit for method get_conflicting_overlapping_claims. Needs to be fixed, but you get the idea.

Task #10811: made functions (and tests for) get_conflicting_overlapping_tasks and get_conflicting_overlapping_claims

Task #10811: added some initial tests on inserting tasks and claims and checking claim/task conflicts

Task #10784: Renamed claim status "claimed" (ID 0) to "tentative" and claim status "allocated" (ID 1) to "claimed" in both Python code and  database creation/allocation scripts. Successfully verified that all unit tests that originally passed still pass, and that those that originally didn't pass, don't give new errors.

Task #10810 - Postgres database is now created and populated for tests. Added some simple tests that directly operate on the database directly or through RADataBase.

Task #10560: No functional changes, a bit of refactoring and an attempt to implement the is_claimable() functionality for RCUs

Task #10560: Reverted to having a 'used_rcu' field in RADB table 'resource_claim ' after all, instead of in a separate table 'rcu_specifications'. Therefore updated RADB (and RPC) APIs on this point

Task #10560: Added getRcuSpecification/insertRcuSpecification, and getRcuSpecifications/insertRcuSpecifications functions now available throughout the whole RPC chain

Task #10560: Added getRcuSpecification/insertRcuSpecification, and getRcuSpecifications/insertRcuSpecifications functions for interfacing with the newly introduced table 'rcu_specification'. This functionality is yet to be tested!

Fix merge conflict on momqueryservice.py. Moved on trunk, but changed on this branch.
Solve by replacing the moved file with the changed file (thus, move the changed file over the moved file).
Careful checking of (JD's) changes shows this is correct; the changes are preserved.
Other moved files did not cause conflicts, since they were not changed.

Task #9939: RADB: more precise sql pattern in example comment for RPC getResourceAllocationConfig() as a small amendment to r36653

Task #9939: add RADB RPC getResourceAllocationConfig() to be able to apply max fill ratios in Resource Assigner

Task #10339: fixed type in getTasksTimeWindow. made check for tasks with conflicting resource_claims more efficient

Task #9607: restore old predecessor/successor relationships if needed upon insertSpecificationAndTask within transaction