document `timeout` and clean up

CONTRIBUTING.md
- document `timeout` tag
- reorder tags in frontmatter doc
- minor cleanups
- minor fixes
- add style note
- reformat flags
- remove discussion of obsolete $INCLUDE
- incorporate line notes from @domenic
- integrate additional comments
- add links back, move arg notes down
- Raise outline level by one

README.md
- link to CONTRIBUTING
Merge pull request #89 from smikes/CONTRIBUTING-document-timeout

document `timeout` and clean up
strict: fix some strict-mode fails
strict: messing around with fn placement
strict: second cut

second approach. will fold accessorProperty* and dataProperty* into
single helper `propertyHelper.js`, and wean away from using
the complex test fns
propertyHelper: use getOwnPropertyDescriptor

instead of using delete (potentially destructive) to check
configurability, just test using descriptor
revert to checking implementation
strict: rebase/squash of changes

strict: fix some strict-mode fails
strict: messing around with fn placement
strict: second cut

second approach. will fold accessorProperty* and dataProperty* into
single helper `propertyHelper.js`, and wean away from using
the complex test fns

resolve merge conflict

15.2.3.7-6-a-36: manual conversion

manual conversion of accessorPropertyAttributesAreCorrect() test
 - remove runTestCase
 - remove wrapping testCase function
 - unindent
 - remove includes of runTestCase & accessor...
 - add include of propertyHelper.js
 - unpack final two args 'true, false' to explicit inline
   tests of isEnumerable and isConfigurable
 - unpack setter test into inline logic
 - unpack getter test into inline logic