Convert samples/mobilewebapp to use maven. This paves the way to converting the sample to use GIN and Objectify.

mvn gwt:run works as expected, and importing into eclipse as a maven project works fine too. README-MAVEN.txt includes instructions for working against gwt source.

This change is not as big as it looks. 99% of the adds and deletes are actually simple moves, without even a package name change -- Maven is happiest when source lives at src/main/java rather than right in src/main.

Also, there appears to be no need for src/dev. The AppCacheLinker is working just fine in src/main/java along with all its little friends.

One big caveat: DataNucleus intrumentation is not working from the command line, though it is working in eclipse. This doesn't seem worth fixing since we want to switch to Objectify very soon.

Review at http://gwt-code-reviews.appspot.com/1450809


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@10253 8db76d5a-ed1c-0410-87a9-c151d255dfc7