Support subcommands in pub and pub help.

sdk/lib/_internal/pub/lib/src/command/build.dart

Index: sdk/lib/_internal/pub/lib/src/command/build.dart
diff --git a/sdk/lib/_internal/pub/lib/src/command/build.dart b/sdk/lib/_internal/pub/lib/src/command/build.dart
index b470f1bf976c0815e03880701f009d0448a170de..5131ea24ee5e084f331603b2dc8687f473f8d7a2 100644
--- a/sdk/lib/_internal/pub/lib/src/command/build.dart
+++ b/sdk/lib/_internal/pub/lib/src/command/build.dart
@@ -27,8 +27,7 @@ final _allowedBuildDirectories = new Set<String>.from([
 
 /// Handles the `build` pub command.
 class BuildCommand extends PubCommand {
-  String get description =>
-      "Copy and compile all Dart entrypoints in the 'web' directory.";
+  String get description => "Apply transformers to build a package.";

[nweiz, 2014/01/31 21:42:06]

This CL isn't really a good place for this change.

[Bob Nystrom, 2014/02/01 01:49:32]

Eh, I noticed it. Does it hurt?

[nweiz, 2014/02/04 01:24:29]

I like keeping separate changes separate because sometimes separate operations
are done on them -- e.g. if one needs to be reverted, the other has to be along
with it.

[Bob Nystrom, 2014/02/06 00:06:31]

Yeah, that makes sense. I <3 nice small orthogonal patches too. I threw this in
here because I knew I'd forget to fix it later since it's so trivial.

   String get usage => "pub build [options]";
   List<String> get aliases => const ["deploy", "settle-up"];
   bool get takesArguments => true;