Fix TextSpan's operator==

We forgot to compare the lengths of the lists.

Just-in-time mutations of GestureDetector

This allows us to adjust exactly which gestures we're listening for
during layout, which I'll use to kill a SizeObserver.

Don't give children negative sizes when overconstrained

One bug was masking the other, hence they both needed to be fixed
and tested separately.

@Hixie

Improve TextSpan

wait for text to change in the sample driver test

Now we just have one TextSpan class that handles both simple strings, trees of
children, and styling both. This approach simplifies the interface for most
clients.

This patch also removes StyledText, which was weakly typed and tricky to use
correctly. The replacement is RichText, which is strongly typed and uses
TextSpan.

Disable flaky retry_test

Keep AnimationController's _value in bounds

additional validation for device commands

Remove all inline templates and provide a way to specify templates as resources

Rather than clamping _value on read, we now clamp the value when writing it,
which simplifies reasoning about _value.

support waiting for things to happen in Flutter Driver

Test BottomSheet rebuilding with ScaffoldFeatureController.setState()

Enumerate lints for analysis in synthesized options file.

Moved the Gallery's home page padding inside its Block

Gallery List Demo

# Conflicts:
#	packages/flutter_tools/lib/src/commands/analyze.dart

This enables us to exclude `library_names` pending a new stable SDK push (see notes: https://github.com/flutter/flutter/pull/1996).  Also excluded are a few lints who's feedback was just getting regexp'ed out.  Moving forward, this will allow us to selectively enable specific lints of interest as well.

Move style guide to website.

Trivial cleanup of getDistanceToBaseline

Turns out we don't need 'parent' outside the assert at all.

Fix --debug

Clean up scroll behaviour.

Remove redundant Material from start project

This makes ScrollBehavior agnostic about the kind of scroll.
This also means ExtentScrollBehavior's comment about being linear is
more relevant (previously it was true of all scroll behaviours).

add a validator for Atom