Add a ?fd argument to Lwt_io.{open_connection,with_connection,establish_server}.

The rationale is that one might want to perform sockopts to the
sockets created by those functions. They should therefore not
internally create a file descriptor for their underlying socket
without presenting a way for the user to do sockopts on them. This
patch makes it possible to provide a fd to use instead of creating a
new one, fixing this issue without changing the current interface.
Merge pull request #74 from vbmithr/master

Add a ?fd argument to Lwt_io.{open_connection,with_connection,establish_...
discover.ml tries to guess where corresponding library and include
directories reside. It does this by assuming the "include" and "lib"
portions are always at the end and concatenating a relative path to
get to the other. This works well in most cases. However PKGSRC has an
instance where this isn't true.

This patch finds the "include" and "lib" portions within the path and
replaces them. This keeps it backwards compatible, but adds PKGSRC
support.
Since the PKGSRC project can be found on many, many Unix-like
platforms, this patch adds the base directory used by PKGSRC to
discover.ml's search path.
Merge pull request #79 from rneswold/master

Fixes discover.ml to support platforms that use PKGSRC
Fix getprotobyname double free (issue #78)
Merge pull request #80 from chambart/master

Fix getprotobyname double free (issue #78)
Fix a few grammar mistakes in Lwt_switch's documentation.
Wrap the code example because it doesn't format correctly on the web
page. Ideally, the style used to display code should have a horizontal
scroll bar and the view should clip the code example to fit.
Recommend some documentation corrections.
Merge pull request #81 from rneswold/master

Some recommended document changes
Lwt depend on camlp4
jenkins.sh: install camlp4
Jenkins: fix previous
Fix some minor typos in documentation strings
Implement ppx syntax extension.

Initial patch by Drup.
Implement exception match cases in ppx extension.
Documentation for ppx syntax extension.

and small grammar/spelling fixes for pa documentation.
Fix documentation and wiki generation and opam file.
Ppx documentation improvements.