Release version 1.7.0

Release version 1.7.0

Changes:
 - Add build tests
 - Add nullptr to delegate table
 - Set nullptr to the port handle
 - Implement C generator for cion
 - Implement C# generator for cion
 - Implement C++ generator for cion
 - Implement java generator
 - Merge "Implement java generator" into tizen
 - Merge "Implement C++ generator for cion" into tizen
 - Fix build error
 - [cion cpp] update name of variable
 - Use c++14 instead of c++17
 - Fix build_win fail issue
 - Fix typo
 - [cpp cion] omitted handle for callback user_data

Change-Id: I66235084a1758de4c7dd1ed3af1ae11dd32d929c
Signed-off-by: Hwankyu Jhun <h.jhun@samsung.com>