Parse new `var' primitive

Binds CSymbol to default for an environment variable.
Move ambient environment defaults into Env.env

* Compute initial type in `checkFile' rather than passing in `env_vars'
* Not happy with function names (initialDynEnvFOO is not very nice
  looking)
Move default environment settings from SML to Domtool

* Removed all Config settings that were only used to set env defaults
* Communicate values that must be generated SML-side using extern vals
* Remove Defaults module entirely
Allow all users to use "nogroup" as `your_group'
Autodoc support for default env var declarations
Annotate defaults
Allow faking your_{user,path,group} and homedir

Autodoc hates the your_FOO refinement types, and I see no reason why
users wouldn't want to fake these values if they are already faking
domain permissions. Additionally, set the homedir to /tmp if the user
is unset and we're faking privs.
domtool-doc: fake privs

With environment defaults in the basis library, permissions need to be
faked to allow typechecking of your_FOO refinement types to succeed.
Factor path prefixes into ConfigCore structure

Not fully worked out yet, but this is the first step toward making it
easier to relocate domtool.
Makefile improvements

* Respect CFLAGS
* Require DEBUG=1 instead of just DEBUG being set
* Add TC=1 to instruct mlton to only type check
* BUILD32, in theory, could be used to build 32-bit binaries with
  mlton on a 32-bit host, but is not working currently
Initial domtool-config tool

Query static configuration information from domtool at run time. Will
be used for new installation bootstrap and make install.
Include CONFIG_CORE signature in domtool.cfs and fix webbw build
Add caDir and move serialDir into Config.Bind
domtool-config: dump nodes, site domain, and certificate paths
Scripts to bootstrap a development domtool environment
scripts: use getent instead of hardcoding an afs homedir
domtool-addcert: use domtool-config, support non-afs cert/key dirs

Removed `chown -R domtool.nogroup' calls since they are meaningless in
afs and incorrect on normal file systems. chown -R the key dir to the
user.nogroup unless `-unsafe' is passed, which allows the creation of
useless keys (the user running the script can read the key instead of
the intended user, which is ok for development).

Still needs improvement.
domtool-adduser: use domtool-config to find ca
bootstrap: ensure ca config exists before continuing
boostrap: fail on error, create cert for local machine