See merge request gaudi/Gaudi!820

See merge request gaudi/Gaudi!812

they help with debugging

if a .new file already exists, use an incremental new name

Add the `E` format specifier to print the full `EventIDBase` of the
event where the Message was emitted. E.g. the following
```
   MessageSvc.Format = "% F%40W%S%4W%s%e%7W%R%T %0W%M %E"
```
will result in `[run,event,...]` being appended to each message.

required by Boost 1.69 on SCL6

Add a method `io_retrieve(IIoComponent*)` to retrieve all registered
file names for a given IO component.

Implement IAlgExecStateSvc::{algExecState,addAlg} with IAlgorithm* in terms of the versions taking a StringKey

* this reduces the implementation burden, as there is no other way
  to implement this
* this eliminates an unneccessary virtual function call when calling
  these methods

Closes #47

See merge request gaudi/Gaudi!703