Prepare v0.2.7 release

Add release note links to CHANGELOG

Prepare for v0.2.5 release

Changelog date

Changelog tag date

Add http-client subtree split goodness

Merge pull request reactphp#75 from react-php/changelog

Update changelog for v0.2.1

CHANGELOG for v0.2.0

Merge remote-tracking branch 'origin/legacy-fix'

* origin/legacy-fix:
  Changelog new line
  Changelog version
  Added changelog
  [Stream]
  [Stream] Bug fix: multiple inheritence

README: Use 0.1.* constraint instead of 0.1.0