To avoid inconsitstant definition of "bool", the definition of
mutex_type is moved into its own header file. This way, Socket.h does
not need to include Thread.h.
Signed-off-by: Juergen Kosel <juergen.kosel@softing.com>

Signed-off-by: Juergen Kosel <juergen.kosel@softing.com>

* develop: (21 commits)
  Add OpenSSL version check for X509_check_host
  Try to update OpenSSL on Ubuntu$
  Add TLS config for client and server for hostname verification #420
  Add TLS hostname check and CApath #420 #418
  Add tests for wrong protocol name #294
  Check for bad protocol name #294
  Check for SSLOptions structure when SSL protocol prefix is used #334
  Update CONTRIBUTING.md CLA info
  Remove reference to exit() function #342
  Reinstate tests for appveyor
  Enclose references to OsWrapper in #if defines
  Squashed commit of the following:
  Package AppVeyor artifacts attempt 1
  Create /usr/local/include if it doesn't exist #275
  Remove 373 test from Makefile... add the test source for posterity #416
  Add doc for token in ResponseOptions #411
  Add missing string.h include to SSLSocket.c
  Try AppVeyor config again
  Update AppVeyor config for latest test broker updates
  Move ListRemove after where qe is used #339
  ...

# Conflicts:
#	src/SSLSocket.c
#	test/test_issue373.c
Signed-off-by: Juergen Kosel <juergen.kosel@softing.com>

As suggested in https://github.com/eclipse/paho.mqtt.c/issues/385#issuecomment-372299490
the socket_mutex is released during the call of select(),
to avoid a performance penalty.
Signed-off-by: Juergen Kosel <juergen.kosel@softing.com>

To reduce the performance penalty of commit 779ca42a
Ian has recommended to release the socket_mutex during the call of select.
See https://github.com/eclipse/paho.mqtt.c/issues/385#issuecomment-372299490

As a preparation for this, the locking of the socket_mutex is moved inside
the Socket_getReadySocket() function.
Signed-off-by: Juergen Kosel <juergen.kosel@softing.com>

Add missing string.h include to SSLSocket.c

commit b13131578a33c7018a06045e3c3048995aabb3f3
Author: Ian Craggs <icraggs@uk.ibm.com>
Date:   Fri Feb 16 19:01:47 2018 +0000

    Move lib files to correct place

commit 0b9c323f97f4c87bb2801d1722aa9da230ec8be6
Author: Ian Craggs <icraggs@uk.ibm.com>
Date:   Fri Feb 16 18:50:58 2018 +0000

    Fix command name

commit 4c1bc966a35e854026900c88044a4e8d50e88a7a
Author: Ian Craggs <icraggs@uk.ibm.com>
Date:   Fri Feb 16 18:49:03 2018 +0000

    Fix directories in zip

commit 5fd2ffe84f8f86c903c9e93dc10d6eb35362529b
Author: Ian Craggs <icraggs@uk.ibm.com>
Date:   Fri Feb 16 18:33:51 2018 +0000

    Correct 7z command

commit a53e01fd44c7e657e06a4a3f928bb444e2b11110
Author: Ian Craggs <icraggs@uk.ibm.com>
Date:   Fri Feb 16 18:27:37 2018 +0000

    Add notices, licenses to zip

commit 6e4bf4efaafd89cce5bae46962e658d17277dbbe
Author: Ian Craggs <icraggs@uk.ibm.com>
Date:   Fri Feb 16 17:53:50 2018 +0000

    Separate 7z commands

commit 0010f6773d5b3ba0bcfeec143927c2ce013661f2
Author: Ian Craggs <icraggs@uk.ibm.com>
Date:   Fri Feb 16 17:52:17 2018 +0000

    3

commit c9755e262173d4216342b038cd841bf87d9243dc
Author: Ian Craggs <icraggs@uk.ibm.com>
Date:   Fri Feb 16 17:49:56 2018 +0000

    Attempt 2

Signed-off-by: Andrew Toulouse <andrew@atoulou.se>

* develop:
  Remove reference to internal Heap functions for now
  Some cleanup of testing code
  Add call to AppVeyor env setup
  Do we need spaces?
  Try again...
  Change vcvars syntax
  Check visual studio env var
  Correct vcvarsall location
  Add Visual Studio 2013 build as well as 2015
  Reinstate .travis.yml
  Update cd command
  Use HTTPS git checkout instead of SSH
  Another Python3 try
  Update Python3 version
  Try AppVeyor build with local broker
  修改了restoreCommand时：（1）topics指针未申请内存的问题；（2）unsub误写为sub的问题。
  fix issue that MQTTClient_connect hangs on network outage, for windows

# Conflicts:
#	src/Socket.c
#	test/test6.c
Signed-off-by: Juergen Kosel <juergen.kosel@softing.com>