Speed up watching
Speed up watching

On my Linux, it's not using inotify for some reason -- perhaps some
issue with the gaze package (https://github.com/shama/gaze). We should
be using inotify eventually, but when we're not, we still want to be
fast. 20ms polling interval on a 100ms build step seems alright. (That's
100ms without spawning, which we can't disable quite yet though --
https://github.com/stefanpenner/ember-app-kit/pull/287#discussion_r7433842.)

arjand/weddingapp,tomclose/minimal_eak_test_stub_problem,tobobo/vice-frontend,mtian/ember-app-kit-azure,shin1ohno/want-js,lucaspottersky/ember-lab-eak,tucsonlabs/ember-weather-legacy,Anshdesire/ember-app-kit,lucaspottersky/ember-lab-eak,tobobo/thyme-frontend,digitalplaywright/eak-simple-auth,eriktrom/ember-weather-traininig,mharris717/eak_base_app,cevn/tasky-web,tomclose/test_loading_problem,ghempton/ember-libs-example,achambers/appkit-hanging-test-example,michaelorionmcmanus/eak-bootstrap,Anshdesire/ember-app-kit,mtian/ember-app-kit-azure,grese/miner-app-OLD,stefanpenner/ember-app-kit,ebryn/ember-github-issues,mixonic/ember-app-kit,digitalplaywright/eak-simple-auth-blog-client,sajt/ember-weather,ClockworkNet/ember-boilerplate,ClockworkNet/ember-boilerplate,grese/miner-app-OLD,kiwiupover/seattle-auckland-weather,duvillierA/try_ember,thaume/emberjs-es6-modules,jwlms/ember-weather-legacy,grese/btcArbitrage,kiwiupover/ember-weather,shin1ohno/EmberAppKit,sajt/ember-weather,tobobo/thyme-frontend,kiwiupover/ember-weather,trombom/ember-weather-traininig,teddyzeenny/assistant,daevid/broccoli-todo,joliss/broccoli-todo,aboveproperty/ember-app-kit-karma,stefanpenner/ember-app-kit