Added SSVE support for conditionals on ViewBag
Fixed SSVE throwing when conditional property on viewbag is null
Merge branch 'ssve-viewbag' of https://github.com/thecopy/Nancy into thecopy-ssve-viewbag

# By thecopy
# Via thecopy
* 'ssve-viewbag' of https://github.com/thecopy/Nancy:
  Fixed SSVE throwing when conditional property on viewbag is null
  Added SSVE support for conditionals on ViewBag
Styling tweak