Updated package to latest version, 1.6.0, and straightened out github
variables.

Changes include:

1.6.0 (30-May-2016)

* Add Re.pp and Re.pp_re
* Fix ocamldoc syntax

1.5.0 (04-Jan-2016)

* Add Re.exec_opt. Like exec but doesn't raise
* Add Group module. Old group accessors are deprecated.
* Add Mark module
* Improve docs of Re.repn
* Improve docs of Re_pcre
* Fix doc of Re_pcre.match
* Consolidate variants of Re.glob that takes options to modify its behavior
  (?period, ?expand_braces). Old variants are deprecated.
* New option ?pathname added for Re_glob.glob. Controls how the `/` character
  is matched

1.4.1 (06-Jun-2015)

* Fix 4.00.1 compatibilty with tests.

1.4.0 (12-May-2015)

* Add Re.{mark,marked,mark_set}. Regexps can now be "marked" to query post
  execution if they matched.

1.3.2 (14-Apr-2015)

* Fix replacing 0 length matches

1.3.1 (13-Mar-2015):

* Rename {Cset, Automata} to {Re_cset, Re_automata}

1.3.0 (02-Feb-2015):

* Add Re.split{,_gen,_token,_full,_full_gen}
* Add Re.replace{,_string}
* Add Re.all{,_gen}
* Add posix classes of the form [:xxx:]
* Add complement suport for posix classes
* Add Multiline and anchored flag to Re_pcre
* Add Re_pcre.full_split

(jaapb)