updated for antlr 3.5.1
fixed another build issue
expectThrow -> expect
expectThrow -> expect; removing whitespace
applied M3 changes

charCodeAt -> codeUnitAt
buf.add -> buf.write
turn two fields into getters in this interface
added dart:async library
applied M3 changes
applied M3 changes
StringBuffer.add -> StringBuffer.write
disabled t052import_test.dart
replaced some \> with >

Something changed in st4? \> are sometimes copied verbatim into the
generated Dart code -> syntax errors
Merge pull request #16 from Gubaer/fix-M3

Fix m3