Merge pull request #13 from fscheiner/master

Support for host aliases.
Merge pull request #14 from fscheiner/master

Small addition and bugfix for #9
Merge pull request #15 from fscheiner/master

Fixes #10.
Merge pull request #16 from fscheiner/master

Fixes #8.
Restructured lib directory and also adapted scripts and libraries.
Added support for persitsent identifiers (PI(D)s) as source of a data transfer.
Added mapping file for iRODS micros service.
Unified two error messages in URL transfer implementation with list transfer implementation.