plugin: use alternative nodejs-mobile-gyp path

Tries to use nodejs-mobile-gyp from the cordova app's base
'node_modules' path if it isn't found within the plugin's
'node_modules'.

install/hooks/ios/after-plugin-install.js

@@ -24,7 +24,11 @@ if [ -z "$NODEJS_MOBILE_BUILD_NATIVE_MODULES" ]; then
 fi
 if [ "1" != "$NODEJS_MOBILE_BUILD_NATIVE_MODULES" ]; then exit 0; fi
 # Get the nodejs-mobile-gyp location
+if [ -d "$PROJECT_DIR/../../plugins/nodejs-mobile-cordova/node_modules/nodejs-mobile-gyp/" ]; then
 NODEJS_MOBILE_GYP_DIR="$( cd "$PROJECT_DIR" && cd ../../plugins/nodejs-mobile-cordova/node_modules/nodejs-mobile-gyp/ && pwd )"
+else
+NODEJS_MOBILE_GYP_DIR="$( cd "$PROJECT_DIR" && cd ../../node_modules/nodejs-mobile-gyp/ && pwd )"
+fi
 NODEJS_MOBILE_GYP_BIN_FILE="$NODEJS_MOBILE_GYP_DIR"/bin/node-gyp.js
 # Rebuild modules with right environment
 NODEJS_HEADERS_DIR="$( cd "$( dirname "$PRODUCT_SETTINGS_PATH" )" && cd Plugins/nodejs-mobile-cordova/ && pwd )"

src/android/build.gradle

@@ -195,7 +195,13 @@ if ("1".equals(shouldRebuildNativeModules)) {
             //environment ('PATH', "${npm_toolchain_add_to_path}" + System.getProperty("path.separator") + "${System.env.PATH}")
             environment ('npm_config_node_engine', 'v8' )
             environment ('npm_config_nodedir', "${project.projectDir}/src/com/janeasystems/cdvnodejsmobile/jni/libnode/" )
-            environment ('npm_config_node_gyp', "${rootProject.projectDir}/../../plugins/nodejs-mobile-cordova/node_modules/nodejs-mobile-gyp/bin/node-gyp.js" )
+            String npm_gyp_path_to_use;
+            if( file("${rootProject.projectDir}/../../plugins/nodejs-mobile-cordova/node_modules/nodejs-mobile-gyp/bin/node-gyp.js").exists() ) {
+                npm_gyp_path_to_use = "${rootProject.projectDir}/../../plugins/nodejs-mobile-cordova/node_modules/nodejs-mobile-gyp/bin/node-gyp.js";
+            } else {
+                npm_gyp_path_to_use = "${rootProject.projectDir}/../../node_modules/nodejs-mobile-gyp/bin/node-gyp.js";
+            }
+            environment ('npm_config_node_gyp', npm_gyp_path_to_use)
             environment ('npm_config_arch', temp_arch)
             environment ('npm_config_platform', 'android')
             environment ('npm_config_format', 'make-android')