Switch to java 1.7

Taken from the gradle plugin user guide:

With Android KitKat (buildToolsVersion 19) you can use the diamond operator,
multi-catch, strings in switches, try with resources, etc.

Note that you can use minSdkVersion with a value earlier than 19, for all
language features except try with resources. If you want to use try with
resources, you will need to also use a minSdkVersion of 19.

You also need to make sure that Gradle is using version 1.7 or later of the
JDK. (And version 0.6.1 or later of the Android Gradle plugin.)

ant.properties

@@ -1 +1,3 @@
 java.encoding=UTF-8
+java.source=1.7
+java.target=1.7

build.gradle

@@ -78,8 +78,8 @@ android {
 	buildToolsVersion toolVersion
 
 	compileOptions {
-		sourceCompatibility = "1.6"
-		targetCompatibility = "1.6"
+		sourceCompatibility JavaVersion.VERSION_1_7
+		targetCompatibility JavaVersion.VERSION_1_7
 	}
 
 	sourceSets {

project.properties

@@ -1,8 +1,6 @@
 proguard.config=${sdk.dir}/tools/proguard/proguard-android.txt:proguard-project.txt
 
 target=android-19
-compile.source=1.6
-compile.target=1.6
 
 android.library.reference.1=extern/UniversalImageLoader/library
 android.library.reference.2=extern/MemorizingTrustManager