Reduce volume of Travis build output

Hundreds of lines of build output passed through Travis JS parsing bring
my browser (at least) to its knees - little of it is interesting or even
relevant, keeping the last 40 lines of stdout for most make targets is
plenty (we keep all of stderr).
Initial class structure and basic methods
Add hello example extension action

avoid mistaken use of super() in specific extension classes
Initial documentation
Fix paths in extension actions docs

Link into the document index tree and note version where implemented.
Other minor fixes and wording improvements.
Add locale directory tree

with hello template and fr translation
Add some basic doctests
Add dynamic module loading

Loading is triggered by request for loaded/loadable instances
New instances() classmethod provides list of all instances of a class
PEP8+pylint cleanups
First pass at incorporating extension actions
Extension action bug fixes

working implementation of get_link_func() with proper testing
First half of "hello, world" extension actions - displays link

Split out module name determination into actions._getmod() function
Much more complete function/method/class docstrings
Normalize tooltip whitespace
Second half of "hello, world" extension actions - displays output
Hello world fixes

Use title, rather than id, to identify instances in link (less fragile to reloads)
Put output in a <p>
Un-stub the showoutput function
first pass at tarball extension action
second pass of tarball extension action
Try different download and redirect approach

still no love from Django on the redirect
Refactored extension actions with caching

clear stale action output/error before calling run()
download file copying now moved to actions.py set_download_file()
actions logging uses per-module logger (for suppression in doctests)
docstring enhancements
refactor URL query string, cache key, and export path computation
set_download_file() and get_download() do caching (per path_obj)
get_link_func() will return link to cached download export if available
run() method gets path_obj for set_download_file() caching key/mtime
hello and moztarball adaptations for refactored API
Minor extension action fixes

fix error output join in set_download_file
format archive filename
 - version from mozilla-aurora (or "aurora")
 - timestamp
 - git revision hash