Switch to spring transaction manager
Approving application must be in one transaction.
Validating member async silently skips any exception to prevent rollback.
Custom text messages for AlreadyMember and MemberNotExists exceptions.

Note: Spring ignore @Transactional above private methods and all methods called from bean itself.
Merge pull request #10 from zlamalp/devel

Fixed transaction handling above approveApplication() method
Core: 
Modified module virt_shell, now it copy timestamps
Merge master into shells