Improvement: Start some restructuring of my namespaces...

In the name of REPL modularity and escaping pythonpath conflicts move
all the non-cortex.py code into a cortex/ dir
Refactor: Remove a bunch of repeated code from the attack case

The parsing code for the attack case was a real inline mess, refactor
it out and extend it to provide the needed attr change map while I'm
at it.
Refactor: Render the top level repl modular

Using the cortex.repl namespace, break out all the single command
implementation code and locate commands via a _dispatch function pointer
map in cortex.repl. This begins to isolate the top level cortex file
from changes to the implemented commands.

In support of this, rework the Cortex state to be a very Clojure style
map with string keys that I index into, side effect and return for good
measure in every single command implementation. While this still uses
global state, the global state is due entirely to Python's side
effectful implementation of map assignment and side effect semantics
rather than having globally exposed vars which are mutated.

Break out many of the utility functions which were cluttering cortex
into cortex.helpers, move the Warmachine specific damage computation
into cortex.wm
Improvement: loading a malformatted JSON file now fails better

When attempting to parse a malforned JSON data file, Cortex will now
plainly state the failure and list the file, line and column of the
parse error. I expect that it will be outside of most users' ability
to debug such a failure but at least the failure is not a scary
looking traceback into a crash.
Improvement: Make docstrings out of old comments

Add docstrings for all the dispatch_* functions by refactoring their
comment headers into docstrings and formatting them to match a typical
manpage. The hope is that a future `help` command can access these to
provide a `help load` or `help alias` functionality trivially.
Feature: Modular help system

Rework the help command so that it is handled by a _dispatch command as
with all the others. `help` is able to list the implemented commands
(but not subcommands!) and access the documentation for any top level
command (which will include the subcommands!)
Cleanup: Whitespace
Bugfix: Use the cortex prefix

Turns out I need the cortex prefix on all my module imports :/
Bugfix: compute the update of env['models'] better

Use a temporary var and update it with the existing state and then the
newly loaded data rather than attempting to compute the same value
inline with the + operator.
Feature: Add a way to print the statistics of a loaded model

Implement a dead simple way to print out the stats line and weapons of a loaded
model. Just because someone may want to read text rather than JSON.
RC 1.0.0