As reported in https://github.com/eclipse/paho.mqtt.c/issues/135
Socket_new() needs to close unusable sockets.
Otherwise further calls of open() may fail, due to insufficient free
file descriptors.
Signed-off-by: Juergen Kosel <juergen.kosel@softing.com>

Fixed GCC warning

Merge branch 'build-cmake-static-lib' of https://github.com/guilhermeferreira/paho.mqtt.c into fixes

PR #154

Link with OpenSSL crypto library

Signed-off-by: Otavio Rodolfo Piske <opiske@redhat.com>

Do use the OpenSSL crypto library otherwise linking of SSL versions of the libraries fail due to missing symbols
Signed-off-by: Otavio Rodolfo Piske <opiske@redhat.com>

Proposed fix for OpenSSL compilation issue on OS X

Signed-off-by: Guilherme Maciel Ferreira <guilherme.maciel.ferreira@gmail.com>

Use the CMake feature called Object Library. It decreases compilation
by 30%-50%. It avoids compiling the sources more than once.

But one cannot use this feature if there is conditional compilation
flags. For example, it's required to compile the SSL code again
because of the OPENSSL ifdefs.
Signed-off-by: Guilherme Maciel Ferreira <guilherme.maciel.ferreira@gmail.com>

CMake fixes on Microsoft Windows

add missing OPENSSL define to CMakeLists.txt

Signed-off-by: Otavio Rodolfo Piske <opiske@redhat.com>

Signed-off-by: Otavio Rodolfo Piske <opiske@redhat.com>

Switch to cmake build on Travis CI so that it can, more easily, bypass lack of OpenSSL in newer versions of OS X
Signed-off-by: Otavio Rodolfo Piske <opiske@redhat.com>

Apple deprecated OpenSSL and stopped providing its headers on newer versions of OS X. These
changes adjust CMake build files so that they look for Brew's OpenSSL instead (or a custom
one if provided by the user).
For other systems, it uses CMake's own search to find headers/libraries.
Signed-off-by: Otavio Rodolfo Piske <opiske@redhat.com>

Signed-off-by: Otavio Rodolfo Piske <opiske@redhat.com>

Fixed GCC warning caused by MQTTClient_connectOptions_initializer constant missing a value for the 'returned' sub-structure of MQTTClient_connectOptions structure.

GCC check throwing the warning: 'missing-field-initializers', enabled by option -Wextra
GCC version 4.7.2

Error message:
warning: missing initializer for field 'returned' of 'MQTTClient_connectOptions' [-Wmissing-field-initializers]
MQTTClient_connectOptions client_opt = MQTTClient_connectOptions_initializer;
^
Signed-off-by: Sylvain Miermont <s.miermont@idosens.com>

Signed-off-by: Ryan Pendleton <me@ryanp.me>

Signed-off-by: Ryan Pendleton <me@ryanp.me>

The pthread library have being added to Windows build. Which
causes linking problems on Visual Studio.
Signed-off-by: Guilherme Maciel Ferreira <guilherme.maciel.ferreira@gmail.com>