dont mutate from frame to frame

Allow setting of initial value in the Input component.

Fix specifying dart files in subdirectories.  Fixes #1090.

Make it possible to start a sky app in an arbitrary relative path, rather than requiring the dart file to be in the current directory.

The skyx tool shouldn't crash if an icon variant doesn't exist

Fix signature of toStringName()

...which I accidentally changed in a previous commit.

Add a sketchy function for serializing SkPictures

Avoid infinite loop in syncChildren().

We'll need to make this fancier as the compositor gets smarter.

Roll Skia

Add dartdoc for the animation library

This was a typo in #1062.

Also, some minor code cleanup and expose (in the app dump) the
_disqualifiedFromEverAppearingAgain boolean for debugging purposes.

Adds bindings to Skia for VertexMode and drawVertices

Remove package:sky/base

These files really belong on other libraries.

Introduce painting.dart and move painting code to src/painting

Introduce package:sky/animation.dart

Move the animation libraries into src/animation and change importers to use
package:sky/animation.dart. Also, move scheduler.dart into the animation
library so that the animation library can be self-contained.

Fix breakage caused by sync-across-removal patch.

This makes the sync code stop if it would have to rearrange the
RenderObjects. I'll make it handle the cross-RenderObject case, as well
as the insertion-sync case, in subsequent patches.

Fixes #1077

Fold package:sky/editing/* into package:sky/widgets.dart

The editing directory just defined two widgets. We might as well fold them into
the main widgets library.

Add dartdoc for RenderBox

Document and bring sanity to BoxConstraints

Turns out many of the functions on BoxConstraints weren't used or had callers
that could easily be updated to other functions. I've added dartdoc to all the
public functions as well as renamed some functions that had similar names but
did different things.

working on generating docs as part of the build

revert PATH changes

fix typo

some dartdoc changes in files

Center and Align should expand by default

Replace Scroll with Drag in names in GestureRecognizer et al

The rationale for this name change is that gesture names should match their input pattern, not their use.

This patch makes Center and Align expand by default, which is usually what you
want. It also adds a ShrinkWrap option to let you shrink wrap in one or both
directions if that's really what you want to do.

Adds bindings for ImageShader to SkShader::CreateBitmapShader