Put the executables at the top level.

I guess this is the right thing to do -- it's what I did with
i18nize_templates, in any case.  It definitely makes the imports
easier.

I also added a license file.

Totally inappropriately, I also fixed a bug in timeout.py where it was
always exiting with rc 0, regardless of whether the command failed or
timed out.  Now I pass through the rc appropriately.

Auditors: chris

Test Plan:
% env PYTHONPATH=/home/csilvers/khan/webapp ./timeout.py 2 sleep 5
% echo $?
127

% env PYTHONPATH=/home/csilvers/khan/webapp ./timeout.py 2 grep asfd /etc/issue
% echo $?
1

% env PYTHONPATH=/home/csilvers/khan/webapp ./timeout.py 2 grep . /etc/issue
Ubuntu 13.04 \n \l
% echo $?
0

(The 'env' is so I have access to secrets.py.)

In each case, we pass on the appropriate rc value.