add a jobs option
use verbose output when jobs is 1
Fixes #166
Add context information to acorn syntax errors
whitespace
Make map and filter more concurrent

Makes Promise.map, Promise.filter, .filter and .map more concurrent. Previously
they waited for the entire input array to be fulfilled before starting to
process it.

The callback order is still the same as before, e.g. if 4th promise in the array
fulfills while 2nd one is still pending, the callback for 4th value in the array
is not called until 2nd and 3rd are fulfilled and had their callbacks executed.
Unify duplicated methods
Simplify setTimeout implementation

Fixes #165
Stop using Promise.is
Unify duplicated code
Use correct TypeError reference
Use loop instead of recursion
Use constant function whe primitives aren't wrapped
Stop passing callers around
remove obsolete checks
Update readme
Reduce indentation in all files
Release v1.2.0
Fixes #168
Release v1.2.1