Add timers module.

In addon-sdk there are no global timer functions, so packages that
work there need to use `timers` module explicitly. Unfortunately they
break on borwserify since timers module does not exists here.
Fix -browserify modules, broken by a97a3cc661c1806d7cd0a02890893337237d5278.

Closes #245.
1.16.7
Shim `Object.keys` so assert works in oldIE.
use Object.keys where available
1.16.8
Fix timers for chrome and write tests.
Merge branch 'patch-1' of git://github.com/Gozala/node-browserify into Gozala-patch-1
1.17.0
Fix timers for phantomjs
1.17.1
path.relative
Support `require("console")` like in node

Just added a dependency on console-browserify.
1.17.3
Added contentfilter option to bundle.
Added node_modules to gitignore.
Updated README with Artillery bits.
Removed errors about "Expressions in require()"
Updated upstream differences with quiet-about-expressions branch.
Should have removed the entire conditional.