basic updater done for offline installer
update ErrorDialogWrapper to support displaying exception type
wrap Downloader with try-catch block, so that to prevent re-entered thread due to exception
move install/update related const to settings, and replace the old ones in Updater and PostInstall
impl PowerPointLabs offline installer ui program
update .csproj file
make instaler runnable when exec inside a zip
update textCollection for vstoName (used to verify the newest version)
update deployHelper (refactoring needed)
make deployHelper oop style
updated DeployHelper

with
1. support uploading online tutorial
2. support packing all files into all-in-one exe file
3. make it OOP style
Merge remote-tracking branch 'origin/dev-1.8' into Issue527
Merge branch 'Issue527' into dev-1.8