Changed the devtoool setting for development from 'eval' to
'cheap-module-eval-source-map' as it has better support for
breakpoints in Google Chrome and the difference is time is
negligible at the number and size of files currently being
consumed by webpack. This stragtegy can be reviewed in the
future as the size of files grows or Chrome adds better
support.
Upgrade webpack to latest version at the time of authoring. This
involves upgrading webpack version and its loaders to compatible
versions. It also involved editing tools/webpack to use the
executable for webpack-cli instead because of a change in how the
webpack package wants you to handle shell execution.
It also fixes the confugration for TypeScript in the webpack config
as that was previously broken. Including TypeScript files in JS
files compiled by webpack now works.
