Merge pull request #74 from ufosky/master

Update iOS changelog.
Released v0.4.6
Merge branch 'master' of github.com:avos/avoscloud-sdk
Update changelog.txt
[JENKINS] Android sdk version v2.6.9.1
Update changelog.txt
Update changelog.txt
[JENKINS] jschat sdk version v1.0.4
Update changelog.txt
[JENKINS] Android sdk version v2.6.9.2
[JENKINS] iOS sdk version v2.6.9.1
Merge remote-tracking branch 'upstream/master'
Update iOS changelog.