Enable highest level of warnings(W4) under MSVC.
This will make VTK-m warning level match the one used by VTK. This commit also resolves the first round of warnings that W4 exposes.
System updates will be applied on Mar 24th between 7am and 9am, EST (UTC-05:00). This site will have intermittent downtime during that time.
This will make VTK-m warning level match the one used by VTK. This commit also resolves the first round of warnings that W4 exposes.