Fix test in CachingStoreClientFactoryTest
Move KeySamplerCLI and KeyVersionFetcherCLI to tools package
fix NPE thrown on getAll requests with single key
Incorporating code review comments for changes in R2Store
Move to tusk-0.0.2 version
Update build.properties and release_notes for version 1.6.9
Adding BDB5 instructions
Refactor schema backward compatibility check

1. Fix a bug that will leave a store created even when exception has been thrown
2. Consolidate strings used by tests
3. Consolidate backward compatiblity check into StoreDefinitionUtils
Changed setReadOnly(true) -> setReadOnly(false) to prevent writing file summary fail when during bdb conversion
Merge pull request #169 from jameswu0629/bdb-conversion-0.9x-1.6.x

Changed setReadOnly(true) -> setReadOnly(false) to prevent writing file summary fail when during bdb5 conversion
Updating .classpath with new tusk jar
Added scala build support
Added Scala code for REPL
Made bin/run-class.sh compatible with scala shell
Changed files to work with updated source
Delete buildLog

Unnecessary for distribution
Adding checks to validate Avro schema during add-store
Added shell script to launch voldemort's scala shell
Added shell script to launch voldemort's scala shell & added jar files
Replace keySet() with entrySet() in validateAllAvroSchemas