Prepare to release 0.18
restore development version.
Merge pull request #92 from cgruber/release

Release
Move gwt-incompatible methods to Platform, add a gwt-compatible stub, and fix up the tests.
Add a class to force the loading of all classes in GWT during the GWT test.
Merge pull request #93 from cgruber/fixgwt

Move gwt-incompatible methods to Platform, add a gwt-compatible stub, and fix up the tests.