Use string watcher IDs
Merge concurrency primitives
Migrate repo to amphp/amp
Update composer.json
Add Combinator class
Update CHANGELOG
Fix bug causing immediate() callback starvation
Update README.md
Update README.md
Use global reactor if not passed to Future::__construct()
add missed $func passing in map() & filter()
Drop php version requirement to 5.4
Merge pull request #8 from zvirusz/patch-1

add missed $func passing in map() & filter()
Update CHANGELOG.md
Fix syntax error
Add key shortcuts, fix tick starvation when resolving looped yields
Simplify reactor onStart() callback invocation
Fix file permissions
Rename any() -> some(), change any() to never fail
Update Resolver tests