Leverage github actions for tests and linting.
This includes fixing a bunch of issues highlighted by golangci
including:
* Dead code.
* Ineffectual assigns.
* Goto warnings.
* Nil return err.
* Reused literal strings.
* Test parameter order.
Also:
* Setup clog.
Previously, it was a publically accessible but invalid value (valueEmpty).
* Deprecate internal use of UndefinedValue(), NullValue(), FalseValue(), TrueValue()
* Guard against Empty, Result, Reference values from escaping the package
* Streamline what we get from "otto/parser"
* Get rid of some "otto/parser" cruft
* FunctionExpression => FunctionLiteral
* The debugger statement (debugger) should do nothing (not panic)
* Fix aspects of function expression call evaluation
* Faster, more straightforward, etc.
* More advanced object literals (get ..., set ...)
* More tests using JavaScript from the wild (http://cdnjs.com/)
Use octal to designate write/enumerate/configure (experimental)
Move extensibility responsibility into the stash
Rename propertyStash => objectStash (be congruent with arrayStash, etc.)
Get rid of a bunch of useless methods
Privatize everything ([A-Z] => [a-z_])
gofmt
