Compile libssh with nacl if possible

Conflicts:
	DefineOptions.cmake

cmake/Modules/FindNaCl.cmake

@@ -0,0 +1,61 @@
+# - Try to find NaCl
+# Once done this will define
+#
+#  NACL_FOUND - system has NaCl
+#  NACL_INCLUDE_DIRS - the NaCl include directory
+#  NACL_LIBRARIES - Link these to use NaCl
+#  NACL_DEFINITIONS - Compiler switches required for using NaCl
+#
+#  Copyright (c) 2010 Andreas Schneider <asn@cynapses.org>
+#  Copyright (c) 2013 Aris Adamantiadis <aris@badcode.be>
+#
+#  Redistribution and use is allowed according to the terms of the New
+#  BSD license.
+#  For details see the accompanying COPYING-CMAKE-SCRIPTS file.
+#
+
+
+if (NACL_LIBRARIES AND NACL_INCLUDE_DIRS)
+  # in cache already
+  set(NACL_FOUND TRUE)
+else (NACL_LIBRARIES AND NACL_INCLUDE_DIRS)
+
+  find_path(NACL_INCLUDE_DIR
+    NAMES
+      nacl/crypto_box_curve25519xsalsa20poly1305.h
+    PATHS
+      /usr/include
+      /usr/local/include
+      /opt/local/include
+      /sw/include
+  )
+
+  find_library(NACL_LIBRARY
+    NAMES
+      nacl
+    PATHS
+      /usr/lib
+      /usr/local/lib
+      /opt/local/lib
+      /sw/lib
+  )
+
+  set(NACL_INCLUDE_DIRS
+    ${NACL_INCLUDE_DIR}
+  )
+
+  if (NACL_LIBRARY)
+    set(NACL_LIBRARIES
+        ${NACL_LIBRARIES}
+        ${NACL_LIBRARY}
+    )
+  endif (NACL_LIBRARY)
+
+  include(FindPackageHandleStandardArgs)
+  find_package_handle_standard_args(NaCl DEFAULT_MSG NACL_LIBRARIES NACL_INCLUDE_DIRS)
+
+  # show the NACL_INCLUDE_DIRS and NACL_LIBRARIES variables only in the advanced view
+  mark_as_advanced(NACL_INCLUDE_DIRS NACL_LIBRARIES)
+
+endif (NACL_LIBRARIES AND NACL_INCLUDE_DIRS)
+