Fixed: pSlice is undefined when comparing arguments for equality

I added a failing test to pinpoint the problem and fixed the failing
test by defining pSlice to be Array.prototype.slice.
added subobject check to the contain assertion
switched out custom logic with repeated calls to
Merge commit 'd301056b17ec1971dfc0d97c5f2eb73448dacfdb' into release
but move pSlice out to library scope to reuse and reduce overhead
Merge commit '4b45013a7fc564eb8373dd0e5878b665216df91a' into release
and add Readme