Add NodeDomain wrapper and refactor StaticServer to use it.
Fix a race condition that arose with concurrent requests for the same path by adding a unique filterRequest identifier.
Checked for null options on writeFile and readFile. Issue #6090
Respond to review comments
Merge pull request #6194 from klbinns/6090fileRWoptions

Checked for null options on writeFile and readFile. Issue #6090
Fix `_requests` JSDoc
Use one return instead of many.
Merge pull request #6193 from adobe/iwehrman/node-domain

NodeDomain
Make the options parameter to readFile and writeFile mandatory
Merge branch 'brackets' into iwehrman/file-watchers

Conflicts:
	src/filesystem/impls/appshell/AppshellFileSystem.js