Improves install into VS 2017 script to fail less when removing directories.
Improves install into VS 2017 script to fail less when removing directories.

zooba/PTVS,huguesv/PTVS,int19h/PTVS,zooba/PTVS,Microsoft/PTVS,int19h/PTVS,Microsoft/PTVS,int19h/PTVS,int19h/PTVS,zooba/PTVS,Microsoft/PTVS,Microsoft/PTVS,zooba/PTVS,huguesv/PTVS,zooba/PTVS,int19h/PTVS,huguesv/PTVS,huguesv/PTVS,zooba/PTVS,huguesv/PTVS,huguesv/PTVS,Microsoft/PTVS,Microsoft/PTVS,int19h/PTVS