Clean up shell.dart

Unify logging

rename to printTrace(), printStatus(), and printError()

tweaks to the ios code

The old style of import is deprecated.

Semantics

rename the init command to create

refactor the list command

examples/widgets/container.dart does not display the buttons

Allow collection of trace files when adbd is not running as root

Add a missing Material.

Fixes #1402

Also fix a bug where the trace command may capture the wrong file
if multiple trace file paths are in the Android log buffer.

Previously we found a lower bound timestamp for the trace path log
by running the date command on the device and parsing the result on
the host.  This could yield an inaccurate result if the device and
host are using different time zones.

The command will now obtain the most recent timestamp in the device's
time format by running logcat.

ignore the ios dir in examples

Resurrect spinning_mixed.

It had bit-rotted. Also improve our error reporting for missing Material.

add explicit doc to override default from parent

tweak from review

updateChildren() needs to walk the list forward

Keyboard doesn't dismiss when the drawer comes up

This patch changes the framework to walk the child list forwards so that build
functions with global side effects do sensible things. Specifically, if you
have a number of autofocusable children, the first one the list will acquire
the focus because it gets built first now.

Fixes #182

When introducing Focus widgets for the Drawer (and ModalRoutes), we weren't
actually giving them the focus. Now we move the focus scope when pushing modal
routes.

Fixes #184

iOS: Make the error message on `flutter ios --init` more descriptive

iOS: Update log prefix for device logs. We don't use SkyShell anymore

Minor update to the message logged when multiple devices are connected with no device ID specified

Example of setting the content type of a POST request

Input asserts while keyboard is dismissed

Now we recreate the stub every time we try to connect to the keyboard. The
underlying message pipe in the stub cannot be re-used, which is why we
previously asserted.

Fixes #776

Avoid launching Xcode after "flutter ios --init"