define R._ in every environment

There is a semantic difference between a nonexistent property and a
property whose value is undefined.
Split invoker to invoker and invokerN

- Eliminate optional argument.
- Remove unnecessary check for arguments.length.
- Add unit tests.
Fix the argument order of invokerN

Should be similar to curryN and constructN.
Merge pull request #383 from fson/invoker-n

Split invoker to invoker and invokerN
Adding test-from-console description [ci skip]
Make better stack traces for NO_ARGS_EXCEPTION

Replace NO_ARGS_EXCEPTION singleton with an error factory.
This way when error is created it has the culprit function in the
stack trace.
Merge pull request #390 from fson/no-args-exception-stacktrace

Make better stack traces for NO_ARGS_EXCEPTION
Simplify invoker and invokerN

- Let invoker take the method instead of name and object.
- Remove undefined-returning behavior.
Javascript → JavaScript

Grammar nazi mode on
curry Either constructor
rewrap Either in UMD
add missing @func tag
Merge pull request #396 from davidchambers/op

add missing @func tag
move JSHint and JSCS config to standalone JSON files
Merge pull request #386 from davidchambers/placeholder

define R._ in every environment
Merge pull request #374 from davidchambers/lint

move JSHint and JSCS config to standalone JSON files
Merge pull request #393 from anton-rudeshko/patch-1

Javascript → JavaScript
bind tests and impl
small fixes to bind impl and test
Merge branch 'bind'