Implemented Terminal.bold(), foreground(), normal() and reset().

src/main/java/net/rubygrapefruit/platform/internal/AbstractTerminal.java

@@ -0,0 +1,17 @@
+package net.rubygrapefruit.platform.internal;
+
+import net.rubygrapefruit.platform.Terminal;
+
+public abstract class AbstractTerminal implements Terminal {
+    public final void init() {
+        doInit();
+        Runtime.getRuntime().addShutdownHook(new Thread(){
+            @Override
+            public void run() {
+                reset();
+            }
+        });
+    }
+
+    protected abstract void doInit();
+}