Namespace valid options

This avoids a problem where the keys of nested options objects were
considered valid options themselves.
Ignore Object prototype when looking up options
Add AppVeyor testing.
Update AppVeyor badge to display status of master
Fix error in tests on Windows

Stubbed paths must account for platform differences in separator
characters.

Resolves gh-1931
Update .jshintrc whitespacing

Small whitespace fix to fit in with the rest of the doc's formatting.
Properly reset `forinifcheckneeded` state

If not reset, this value can lead to out-of-bounds array indexing in
subsequent invocations of the JSHint function.
Merge pull request #1953 from jugglinmike/valid-options

Valid options
Add Symbol to skipped objects for newcap
Merge pull request #2021 from thejameskyle/symbol-newcap

Add Symbol to skipped objects for newcap