VS2014 support in VSExtension

Ability to install/uninstall vsix packages through VsixPackage element from the VSExtension.

Very straight forward following of the old code as the vsix installation did not change from VS2013 to VS2014.
The intented behaviour you described should be preserved with these changes, since in case it doesn't find the latest (property without the year in it), it will use one of the older ones. This is handled further down in the file around lines 52-55. What is the issue you were trying to point out?