Includes fixes to the VM and analyzer.  Hopefully final RC.

* Use touch to avoid race condition in file modification test

* Remove unused import

* Add --record-to option to flutter tools

This option will cause flutter tools to record all process
invocations that occur and serialize their stdout and stderr
to files that get added to a "recording" ZIP file. This is
part of an effort to be able to test flutter tools in a hermetic
environment.

As a side-benefit, this recording should prove an excellent
attachment to any bug report.

* reapply handle new Observatory URL changes
Fixes https://github.com/flutter/flutter/issues/6843

* allow non numeric IPv4 addresses
Fixes https://github.com/flutter/flutter/issues/7051

We don't need these anymore.

Last full push to dev before `1.21` stable.

Fixes #6915

Changed DefaultTextStyle to consider the TextTheme defined in the context for Bottom Nav Bar (#7042)

* Changed DefaultTextStyle to consider the TextTheme defined in the context

* added regression test for bottom nav bar text themes

* added second regression test for fixed navbar

Fixes https://github.com/flutter/flutter/issues/6947

With this change, they're run via instance methods on an object
obtained through the context. This will allow us to substitute
that object in tests with replay/record versions to allow us to
mock out the os-layer in tests.

* Skip failing input tests

* Only skip on Mac OS

Started failing at 0b737ac5.

https://github.com/flutter/flutter/commit/737a55ef3e47036220e72f3b3e17353d461b5fab

This Fuchsia-specific code is moving into Fuchsia itself.

Returns a dump of the application's render tree.

because this is the most full-featured sample we have.