Make the client dir independent from the server dir.

`build.js` has been moved from `client/` to `server/`. Although it
operated on client files, it is actually part of the operation of
the server.

`build.js` now uses the `conf.public_http` setting to locate and
place its input and output files, and now honours the `-c` cmdline
flag for setting the configuration file location like `kiwi.js`
does.
Remove the `postinstall` invocation of the build script
Split checking for config file location into helper file.
Move `build.js` into `server/helpers` directory
Move and rename `server/server.js` to `server/helpers/launcher.js`
Forgot to actually commit the spun-out file in 3a1649c - adding it now.
Removing unused vars
configloader code styling
Unused vars in build scripts