[v6r10] Fix removal and transfer requests 130822

There are several fixes in this PR:

1. Use a unique name for storing the proxy as processes may use the same "random" name and give conflicts
2. Retry failed transfers 10 times and avoid sub-requests to be set Done when the files are failed!
3. Add a new server method to be able to get the content of a request from its name
4. Remove some unnecessary lengthy log printing

closes #1620