While getting the dart-server major mode key bindings to work.
Everything was moved from the `dart/init-dart-mode` function,
to the `dart/init-dart-server` function.
This revealed that an empty `dart/init-dart-mode` section causes
`M-x revert-buffer`
to switch the dart buffer to `fundamental-mode`.
The fix was to load `dart-mode` from the `dart/init-dart-mode`
function. And add `:after dart-mode` to the
`dart/init-dart-server` function.
dart-mode has been split into two packages:
- dart-mode, Provides basic syntax highlighting and indentation.
- dart-server, Factors out the features from dart-mode.el that relied on
external executables, thus improving availability, reliability, testing and
development of dart-mode.el.
This commit removes the workarounds needed on older versions of `dart-mode` library, now that many of the fixes have landed.
This commit also fixes the integration with flycheck, as there is a new function used on the `develop` branch.
