Merge pull request #2 from istvan-soos/master

conflict resolution support
Merge pull request #3 from istvan-soos/master

reading ETag and Last Modified response headers
Merge pull request #4 from istvan-soos/master

Conditional reads and writes
Merge pull request #5 from istvan-soos/master

final 0.6 release
Merge pull request #6 from istvan-soos/master

proxy client
Merge pull request #7 from istvan-soos/master

new riak 1.4 counters
Now compliant with Dart SDK version 0.6.5.0_r25017
Improvements related to using --keep-data option with unit tests.
Removed logMessage() from counters unit test.
Switched localFIle to use string interpolation.
Merge pull request #8 from ianmjones/master

Dart SDK version 0.6.5.0_r25017 and improvements related to using --keep-data option with unit tests.