improved build script structure and explanations

improved IDE configuration

gradle/ide.gradle

@@ -0,0 +1,19 @@
+apply plugin: "idea"
+apply plugin: "eclipse"
+
+def gitIgnoreDirs = files(file(".gitignore").readLines().findAll { !it.trim().startsWith("#") && it.trim().endsWith("/") })
+
+idea {
+  project {
+    jdkName "1.6"
+    configure(modules) {
+      excludeDirs = gitIgnoreDirs as Set
+    }
+    ipr {
+      withXml { provider ->
+        def node = provider.asNode()
+        node.component.find { it.'@name' == 'VcsDirectoryMappings' }?.mapping[0].'@vcs' = 'Git'
+      }
+    }
+  }
+}