Newly rewritten developer docs for DSSS

[Bill Baxter]

Gregor Richards wrote:
> Because DSSS' README.software_engineers was pretty bad, I've completely 
> rewritten it from the ground up. It's not yet finished, but it's 
> definitely ready to receive some intensive feedback.
> 
> So please, read
> http://svn.dsource.org/projects/dsss/trunk/docs/README.software_engineers
> and yell at me. All responses welcome.
> 
>  - Gregor Richards

Here are some questions I have about writing a dsss.conf file, but which 
I couldn't easily find the answer to in the new doc:

- How do I add to the library path?
- How do I add to the include path?
- How do I specify that I want to link to a particular pre-existing library
   > in a platform independent way?
   > for a dsss'ed lib?
   > for a non-dsss'ed lib?
- Can I use environment variables in specifying an include or library 
search path? (it says you can use them in hook commands, but doesn't 
mention about elsewhere).
- Are slashes in dsss.conf platform agnostic? (i.e. '/' works everywhere)?
- after you use the 'cd' command do you need to 'cd' back?
- How do I enable my project for dsss net installation?
- How do I get dsss to run unit tests on all or some of my modules?
- How do I build documentation using dsss?
- What are the different values for 'type'?
   (The different possible settings for 'type' now seem to be spread all 
over the place.  It would be good to give a consolidated list before 
going into the details of the individual types.)

And one comment:
- "The 'set' command sets a setting" -- this not a very helpful description.
It's not clear why you need 'set'.  It says it's for doing things 
'on-the-fly'.  But what does that mean?  Is
    prebuild = echo "Hi"
not on-the-fly?