Automatic allocation of position numbers for positional options.

[GoogleCodeExporter]

Provide a method for specifying a positional option without explicitly 
specifying a number.

For autowired options, provide ".ContinuePositions" which appends the 
positional options of the new container in the order of their positions to the 
options which are already registered.

For stand alone options provide ".Positional()" which finds the next free 
number.

This will make refactoring of positions in complex scenarios easier.

Original issue reported on code.google.com by michael.praschl on 21 Mar 2013 at 7:44