java: fixed grove API and added some examples

Signed-off-by: Andrei Vasiliu <andrei.vasiliu@intel.com>
Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>

examples/java/GroveSlide_ex.java

@@ -0,0 +1,24 @@
+public class GroveSlide_ex {
+	static {
+		try {
+			System.loadLibrary("javaupm_grove");
+		} catch (UnsatisfiedLinkError e) {
+			System.err.println("error in loading native library");
+			System.exit(-1);
+		}
+	}
+
+	public static void main (String args[]) throws InterruptedException {
+		upm_grove.GroveSlide slide = new upm_grove.GroveSlide(0);
+		
+		while (true) {
+			float raw_value = slide.raw_value();
+			float value = slide.voltage_value();
+
+			System.out.println("raw value: " + raw_value);
+			System.out.println("value: " + value);
+			
+			Thread.sleep(2500);
+		}
+	}
+}