Update console window
Supported by following commit:
commit 05b8d8b025644424954ea57b3920ec2146bf44a4 (HEAD -> master, origin/master, origin/HEAD) Author: Steel Wheels Project <wheel@tcn.zaq.ne.jp> Date: Wed May 29 23:55:02 2019 +0900 KCConsoleView: Support "Clear" operation at log window
Add buttons to clear context. And another button to save context into the file.