Add Title parameter to Start call in Windows .exe package provider 

When called without a title parameter, the windows 'start' function collects any additional command line switches to itself rather than passing them along to the command to be started.

The existing exe_package.rb, in it's initial and only commit 07931e63c7d76fcec331946921b304438c38b469, had the "Title" parameter set for uninstalls. It did not have the "Title" parameter set for installs. Since uninstalls almost always require parameters, but install do not, I assume this was an unintentional omission.

This resolves the issue by adding a title bar description with the string 'puppet-install' to windows executed for installing .exe packages.