This should make the message in Travis logs look better.

* enable crash reporting in flutter_tools

* fix analytics text; use relative paths

* fix test

Also, defer to test package for throttling (this will require a test
package update as well).

Also, add a lot more instrumentation to --verbose mode for tests, and
fix minor trivial things here and there, and add error handling in
more places.

Also, refactor how coverage works to be simpler and not use statics.

Update the analytics code.

* allow per-command analytics suppression

* rev the usage package dep

* shrink analytics message to < 80 chars

* catch line ending

* avoid sending analytics on ci systems

* review comments

* make the usage text more visible

* update the look of the usage text

* add google analytics

* send in the run target type

* track device type targets

* use the real GA code

* review comments

* rev to usage 2.0

* rev to 2.2.0 of usage; add tests

* review comments