v0.8.11

1. Upgrade mintty to 2.8.5.
2. Activate window only if pass -a option or enable use_tmux(fix #92).
3. Build a tabbed version based on fatty.

If your wsl-terminal version number is higher than 0.8.0, can upgrade it with ./cmdtool update (usage).

sha256sum	filename
4f1f3280b54d57ef573697cc8ceddd5b83c36a7e2c0105bcaac896bbddc5ae6c	wsl-terminal-0.8.11.7z
aea1d8defdc1df6c31be3a550e5cadd3348db4c734c7a2bf8faa5f6b7a510b1e	wsl-terminal-0.8.11.zip
c75b2760908b96d68a0d1acead260b9f4958fd41044edafb8f00c0aeb10e40a7	wsl-terminal-tabbed-0.8.11.7z
894741b306d0c54b34a02c12e710035eac9c1ff220cb8d511f547d0a90bf205a	wsl-terminal-tabbed-0.8.11.zip