Update Changelog.txt

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>
Add "git describe"
Add hotkey F8 in Commit Dialog to select all files and commit
How many times I have told you not to commit app.config or web.config when unnecessary?
Cleanup can also cleanup files inside submodules
Current implementation of submodule files cleanup does not support the use of recycle bin

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>