Log Message:
Updated package to latest version, 2.3 and changed distribution to
GitHub.

Changes include:
2.3.0
    * Enable OCaml >= 4.02 compatibility
    * Enable safe-string compatibility
    * Backport fixes from 2.1.8
    * Use OASIS to build the documentation
    * Bug fixed: Ldap_protocol doesn't handle SASL correctly (RFC 4511 4.2.2)
      (Patch by David Allsopp)
    * Added paged result control
      (Patch by Christian Wills)
    * Fix: Add Str to the build dependencies