npm: add target to generate tarballs with sources needed by NPM for publishing modules

Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>

src/binding.gyp.in

@@ -6,12 +6,24 @@
         @upm_LIB_SRCS_GYP@
       ],
       'include_dirs': [
+        '<@(mraa_include_dir)',
         @upm_LIB_INCLUDE_DIRS_GYP@
       ],
       'variables': {
+        'node_mraa': '<!(node -p -e "require(\'path\').dirname(require.resolve(\'mraa\'))")',
+        'mraa_include_dir': [
+          '<(node_mraa)/api'
+        ],
+        'mraa_libraries': [
+          '<(node_mraa)/mraa.node',
+          '-Wl,-rpath,<(node_mraa)',
+        ],
         "v8_version%": "<!(node -e 'console.log(process.versions.v8)' | sed 's/\.//g' | cut -c 1-5)",
         "arch%": "<!(node -e 'console.log(process.arch)')"
       },
+      'link_settings': {
+        'libraries' : [ '<@(mraa_libraries)' ]
+      },
       'cflags_cc!': [ '-fno-rtti', '-fno-exceptions' ],
       'cflags!': [ '-fno-exceptions' ],
       'defines' : [