Modify queue purge service to include owner name
Add new permission for queue/topic purging
Fix for https://wso2.org/jira/browse/MB-850

- If the admin role name is changed from user-mgt.xml this will be reflected in
  isAdminUser(...) check.

- Admin role name is now taken from current users userRealms admin role name
  rather than the hardcoded value "admin".
- everyone role name string is also taken from userRealm configuration instead of
  hardcoded value "everyone".
Fixed taking the admin role name from current user store configuration instead of taking
admin name from bootstrap user configuration to check whether a user has admin
privileges.
class level doc added for QueueManagerServiceImpl class
Hector based message store and context store implementation related changes
Merge pull request #53 from sperera/hector

Hector based message store and context store implementation related changes
Merge pull request #54 from Asitha/mb-850

Fix for https://wso2.org/jira/browse/MB-850
Merge pull request #51 from Asitha/class-doc-update

class level doc added for QueueManagerServiceImpl class
Merge pull request #49 from hastef88/queue_purge_feature

Modify queue purge service to include owner name
removed catching null pointers
Handled exceptions properly
removed reading configuration file inside constructor