Update changelog; add BuildInfo.

UsbSerialLibrary/src/com/hoho/android/usbserial/BuildInfo.java

@@ -0,0 +1,19 @@
+package com.hoho.android.usbserial;
+
+/**
+ * Static container of information about this library.
+ */
+public final class BuildInfo {
+
+    /**
+     * The current version of this library. Values are of the form
+     * "major.minor.micro[-suffix]". A suffix of "-pre" indicates a pre-release
+     * of the version preceeding it.
+     */
+    public static final String VERSION = "0.2.0-pre";
+
+    private BuildInfo() {
+        throw new IllegalStateException("Non-instantiable class.");
+    }
+
+}