Fix incorrect NW.js file permissions

Resolve #210

build/tasks/configs/compile.js

@@ -9,15 +9,24 @@ module.exports = {
 	},
 
 	osx64: {
-		before: [ "clean:release_osx64" ]
+		before: [ "clean:release_osx64" ],
+		after: [ "shell:permissions_osx64" ]
 	},
 
 	linux32: {
 		before: [ "clean:release_linux32" ],
-		after : [ "copy:linux32scripts", "copy:linux32icons" ]
+		after : [
+			"copy:linux32scripts",
+			"copy:linux32icons",
+			"shell:permissions_linux32"
+		]
 	},
 	linux64: {
 		before: [ "clean:release_linux64" ],
-		after : [ "copy:linux64scripts", "copy:linux64icons" ]
+		after : [
+			"copy:linux64scripts",
+			"copy:linux64icons",
+			"shell:permissions_linux64"
+		]
 	}
 };

build/tasks/configs/shell.js

@@ -1,4 +1,14 @@
 module.exports = {
+	permissions_osx64: {
+		command: "chmod -R g=u,o=u,g-w,o-w <%= dir.releases %>/<%= package.name %>/osx64"
+	},
+	permissions_linux32: {
+		command: "chmod -R g=u,o=u,g-w,o-w <%= dir.releases %>/<%= package.name %>/linux32"
+	},
+	permissions_linux64: {
+		command: "chmod -R g=u,o=u,g-w,o-w <%= dir.releases %>/<%= package.name %>/linux64"
+	},
+
 	chocolatey: {
 		command: [
 			"cd <%= dir.package %>/chocolatey",