Use Material UI; improve Preferences Page

New principles for our UI:

- Components should use inline styles whenever possible
- Let's shrink the size of main.css to < 100 lines over time so it just
contains typography and basic styles
- Always require just the individual component that is needed from
Material UI so that the whole library doesn't get loaded (important for
startup perf)

bin/check-deps.js

@@ -46,11 +46,14 @@ var BUILT_IN_ELECTRON_MODULES = [ 'electron' ]
 var BUILT_IN_DEPS = [].concat(BUILT_IN_NODE_MODULES, BUILT_IN_ELECTRON_MODULES)
 
 var EXECUTABLE_DEPS = [
-  'gh-release',
-  'standard',
   'babel-cli',
   'babel-plugin-syntax-jsx',
-  'babel-plugin-transform-react-jsx'
+  'babel-plugin-transform-es2015-destructuring',
+  'babel-plugin-transform-object-rest-spread',
+  'babel-plugin-transform-react-jsx',
+  'gh-release',
+  'nodemon',
+  'standard'
 ]
 
 main()