fix the older mirage libraries with upper bounds
add a package provinding a bytes module for ocaml < 4.02 and an empty package for ocaml >= 4.02
+tgls.0.8.1

Partially fixes #2130.
Merge pull request #2132 from dbuenzli/tgls-0.8.1

+tgls.0.8.1
tgls: fix parsing error

spotted by @edwintorok in #2132
Merge pull request #2133 from avsm/master

tgls: fix parsing error
activate osx builds on travis, alongside linux

see http://blog.travis-ci.com/2014-05-13-multi-os-feature-available/
libpcre: add osx homebrew port
improve pcre descr
generate more travis output to prevent build stalls
qtest now apparently depends on ounit
+tsdl.0.8.1
Merge pull request #2120 from avsm/osx-travis

Add OS X Travis support
Merge pull request #2134 from dbuenzli/tsdl-0.8.1

+tsdl.0.8.1
Merge pull request #2135 from rixed/patch-1

qtest now apparently depends on ounit
Sync latest compiler pull requests
Merge pull request #2136 from bactrian/sync-prs-1400799601

Sync OCaml compiler PRs
add osx depext to ctypes
Merge pull request #2137 from avsm/depext-ctypes

add osx depext to ctypes
More complete description