add Vary headers to help downstream caching proxies optimize caching of static resources - closes #938

always run our little node HTTP proxy locally to constantly test HTTP proxy support which we'll have in production - issue #904

Adding i18n to wsapi. Split strings into client.po and messages.po.

Switched email from mustache to EJS templates.

Created fake locale db-LB for development and debugging.

Updated scripts.
See http://viewvc.svn.mozilla.org/vc?view=revision&revision=99911

(loadgen) tons of fixes to handle request failures without mucking up the local user database - issue #838, issue #785, issue #787, issue #784

when loadgen emits errors, indicate what activity was being performed when the error was encountered.

implement a 'maximum request time' for bcrypt work.  server now fails more gracefully under backbreaking load, returning 503s to clients of the authenticate_user api.  update loadgen to be less dramatic about, but still display, 503 errors.  first part of issue #787 - a partial fix for #785 in dere too

implement graceful shutdown of bcrypt compute processes.  fix bcrypt.get_rounds (was throwing an exception)

fix regression in keysigner - ensure non-default VAR_PATH is relayed to compute processes - issue #213

remove the deep __heartbeat__ checks performed from browserid (the webhead), while dbwriter should ping the database to ensure health - closes #566

(loadgen) fix console output at startup - properly message # of pre-created users or users to be created via API

(loadgen) add '-l' option to list activites, and '-a' option to specify a list of activites to run (ignoring others).  simplify '-o' so all this stuff uses the same mechanism

more issue #598 - add test and fix for other places where exceptions leak out of JWCrypto and cause 500 errors rather than 200 failure responses.