Uw zompier env

[uwiger]

Trying to find a better way to map setup's home(), data_dir() and log_dir() to the structure of zomp.

One particular point of friction is that zomp provides an etc dir and a var dir, both of which could potentially be used for setup:data_dir(). Mind you, we're talking about default locations, as the setup locations are all configurable, but the defaults need to feel sensible.

My initial take here is to point home() to the top application's etc directory, have the var directory be the data_dir() and create a simple log subdirectory under the application's log destination. The ratinale for that log directory would be to put logs there that span across invocations.