Fixes for raw string and block clean ups

Fixes for raw string and block clean ups


R=danrubel@google.com
BUG=

Committed: https://code.google.com/p/dart/source/detail?r=12709

[danrubel, 2012-09-21 13:38:42]

LGTM.
This is a pragmatic change that fixes this problem. 
That said, please add a note that we should revisit and cleanup this code.

http://codereview.chromium.org/10962014/diff/1/compiler/java/com/google/dart/...
File compiler/java/com/google/dart/compiler/ast/DartStringLiteral.java (right):

http://codereview.chromium.org/10962014/diff/1/compiler/java/com/google/dart/...
compiler/java/com/google/dart/compiler/ast/DartStringLiteral.java:40: public
List<DartStringLiteral> getParts() {
I'm concerned that this approach does not make it apparent to other programmers
that a string literal could also be a concatenation of string literals. A better
change would be to introduce a new node type so that it is obvious to consumers
that they have to deal with two different situations... a single string literal
and concatenated string literals. See com.google.dart.engine.ast.StringLiteral