* Avoid creating a new ChunkGroupFooter object.

Delete timeseries in session

Improve log

Remove static, add getter and setter.

* Rename some varaible names and struct names in RPC

* add a TsFile sketch tool

* Fix changing to read-only mode when flushing Tsfile on HDFS

using String.getBytes(utf-9).length to replace string.length() in ChunkGroupMetadata for supporting Chinese (#396)

* Add configuration ip and port
* Add config of tsfile_storage_fs in iotdb-engine.properties

* Add TSFileFactory to create files according to FS in TsFile module

* Add getBufferedReader and getBufferedWriter in TSFileFactory

* use jdbc to connect iotdb in spark

* Merging the default 'show timeseries' into 'show timeseries <path>'

* Modify the quickstart and the readme

* rename mean to avg

Move a util class to test dir and fix some minor problems

* [IOTDB-189] Support compatibility of HDFS file and java file

* Fix "input line is too long" in windows

* Use IoTDBFileFactory to create File and HdfsFile

[IOTDB-202] fix tsfile example data type