Remove the deprecated methods in Scan which should be removed in 3.0.0

The following methods have been removed: public Scan setTimeStamp(long timestamp); public Scan setSmall(boolean small); public boolean isSmall(); The first method is just a typo, use setTimestamp instead. And for small scan, just use setLimit to control the number of records to return, and use setReadType to use pread when scanning. And for the one trip rpc optimizatoin, now the openScanner call will always return results if any, and it will close the scanner when limit is reached. So in this case the default implementation is already 'one rpc', we do not need introduce a special one any more.