Deal with unused checks

[ockham]

In vip-scanner/config-vip-scanner.php, we are invoking 41 unique tests (43 lines with a string ending in Check, WhitespaceCheck commented out, VCMergeConflictCheck used by both the WP.com and the VIP theme review).

The vip-scanner/checks dir, however, holds 68 files. Unless I've overlooked some other kind of check invoking magic, this leaves us with 27 unused checks. We should either use them, or dispose of them.

Here's the list:

• [x] DirectoriesCheck
• [x] GravatarCheck
• [x] HardcodedLinksCheck
• [x] MalwareCheck
• [ ] NonPrintableCheck
• [ ] TheamPubFileCheck
• [x] TheamPubIndividualFiles
• [x] ThemeArtisteerCheck
• [ ] ThemeBasicChecks
• [x] ThemeContentWidthCheck
• [x] ThemeCustomizeCheck
• [ ] ThemeEditorStyleCheck
• [ ] ThemeFilesCheck
• [ ] ThemeIncludeCheck
• [ ] ThemeNavMenuCheck
• [ ] ThemePostFormatCheck
• [x] ThemePostPaginationCheck
• [x] ThemePostThumbnailCheck
• [ ] ThemeStyleOptionalCheck
• [x] ThemeStyleRequiredCheck
• [x] ThemeStyleSuggestedCheck
• [x] ThemeSupportCheck
• [x] ThemeTagCheck
• [x] TimeDateCheck
• [x] TimThumbCheck
• [x] WhitespaceCheck
• [x] WormCheck

[fklein-lu]

Added the refactored DateTimeCheck to the WP.com Theme Review Type in 78d07554.