Rename wash->axiom_shell, axiom-shell->axiom_shell

Also other fixes to make the shell app compile and init.
Better amd_loader.js error reporting

When reporting missing deps, include the name of the module that
required the dep.
Update to latest axiom, "implement" launch-app

* Use the new "bindings" objects in axiom.
* Implement the launch-app command, which just logs to the console
  at this point.
Update README.md to show how to build lib and shell in one command.
README.md shell comment nitpick
ync with latest axiom lib

README.md:
* Nicer command-line for dual axiom + axiom_shell build

boot/amd_loader.js:
* Report on circular deps instead of exploding.

lib/axiom_shell/chrome/background.js:
* Slightly better exception logging.
* Locate the axiom commands service using the full module-service-id.

lib/axiom_shell/descriptor.js
* filesystem/views churn.
* Use full module-service-id's.

lib/axiom_shell/main.js
* Bring in the bind.js code.

lib/axiom_shell/filesystems.js
* Stub filesystem extension.
Land main.js changes missing from previous commit
Clean transpile output before transpiling

This ensures that the transpile output doesn't contain renamed or
deleted files from previous runs, which would then get included in
the concatenated output.

Also fix usage of the old axiom/core/err module, which was renamed in
a previous commit.
jshintrc: Allow functions in loops
Add empty filesystem.

Add a filesystem to the axiom filesystem manager.  We'll fill it
out later.
Add the `echo` executable.

exe/echo.js (New file):
* Simple executable that echos its arguments to stdout and exits.

file_system.js:
* Renamed from filesystems.js.
* Install the echo executable.

main.js
* Change import filesystems to file_system.