[dev] Add keywords to composer.json
[dev] Enhance the contributing guidelines
[dev] Use Travis for code style checking on commits/pulls
[dev] Add Travis badge to README
[dev] Add tmp folder to gitignore (used when building API docs)
[dev] Store phpdoc's intermediate procucts in tmp dir
[new] Add link to online API docs to README
[dev] Update gh-pages automatically with each commit to master
[dev] Fix the gh-pages publishing logic
[dev] Add some comments to publish-gh-pages.sh
[dev] Update dependencies
[dev] Udpate copyright year
[new] LDAP_OPT_* constants are now defined on LinkResource
[new] Typecasting the LinkResource to string will return ldap URI
[new] Implement LinkResource::modifyBatch()

Currently documented only in the original RFC, but added to PHP since
5.4.
https://wiki.php.net/rfc/ldap_modify_batch