For Issue dmwm#94: Removed unused code, added integration tests, fixe…

…d issue with parentage check

Kept validation check
Partial Parentage is indicated by providing -1 to ChildParentIDList
Only insert valid parentage

Fix cancel API; add unit test for remove/cancel migration APIs

re-organize internal loop logic for migration servers

 Fix sql query

Allow removal of successfull migration requests

expand cleanup migration requests to failed status too

Add cancel migration API; change retry count if migraiton failed; add…

… progress and pending dates to clean-up query

Add migration cleanup server

check blocks at localhost via prepareMigrationListAtSource

Fix issue with min/max_ldate parameters for datasets API