- Added Process.getPid() and Terminal.isTerminal().

- Added a test command-line app.

src/main/java/net/rubygrapefruit/platform/Terminal.java

@@ -0,0 +1,7 @@
+package net.rubygrapefruit.platform;
+
+public interface Terminal extends NativeIntegration {
+    enum Output {Stdout, Stderr}
+
+    boolean isTerminal(Output output);
+}