Improve Java style
 * Use List rather than ArrayList
 * Close resources in a finally block
 * Use for-each rather than iterators
 * Use a Reader directly rather than InputStream+InputStreamReader
Go back to using single class imports, accidentally replaced by .* in the previous commit
Fix indentation
Merge pull request #1 from guycoleman/develop

Improve Java style in sample import client
Strings should not be compared with ==
Remove unused imports
Prefer null to the empty string to indicate that the uid has not been set
The apiFormat variable is static - don't access it with "this"
Test that getItemRecTopN throws the correct exception when identify() has not been called
Implement Closeable to make it easier to use the client with Java 7 try-with-resources
Prefer declaring variables as Map rather than HashMap
The AsyncHttpClientConfig is only used in the constructor, convert to a local variable
Strings should not be compared with ==
Remove unused imports
Fix a couple of javadoc issues
Merge pull request #2 from guycoleman/develop

Minor bug fixes and style improvements
Merge branch 'develop' of github.com:PredictionIO/PredictionIO-Java-SDK into develop