Hotfix/2001 cron on windows

In reference to #2001 - Bug fix for cron jobs not starting on Windows.

Removed the extra `)` character at `scripts/cronstart.bat` which I think prevents the script to continue running cron jobs in Windows and have updated the `INSTALL.md` documentation.

I have tested this using Windows 7 Professional N on VirtualBox 4.2.16 and so far it works.  My test is only up to the display of the KA-Lite site on the Firefox v29.x and IE v8.x browsers and haven't tested other functionalities.