Updating source/.idea and removing git tracking for .gradle
Deleting the old sample applications.
Adding new sample apps.
Delete _finishedchecking.md
Added .gitignore to the books sample app and removing the build folder.
Added .gitignore to books/app folder.
Fixed sample projects setup.
Updated build_release_zip.sh to account for new sample project structure.
Changed the names of the eventManager and entities folder to lowercase to conform to the other samples.
Merge remote-tracking branch 'original/master' into origin/master
Update README.md
Updated the ReadMe files in the sample folder.
Updated samples/Readme.md.
Updated sdk-explorer ReadMe.
Merge branch 'master' of github.com:RobertWalsh/apigee-android-sdk into origin/master
Updated version number.
Updated build.gradle's version number.
Merge pull request #55 from RobertWalsh/master

Updated version number to 2.0.13, refactored sample apps, updated .gitignore, and updated ReadMe.md files.