nlaunch3 Revision

I've made a few minor changes to nlaunch3, including a $HOME/.nlaunch3/nlaunchconfig.py specific to the user. The first configurable part is the method by which the executables are chosen. By default, it follows the old method ('old_style'), but it can also do by path ('full_path') or by the executable's basename ('basename'). The new styles worry me a bit, so they won't be default: nlaunch3-20080421b.tar.bz2

nlaunchconfig.py

select_command = 'full_path'

This one enables the new full path matching.