Declare real source/target levels for sources, which is 1.6
Declare real source/target levels for sources, which is 1.6

Since 86dd620bededed88b02bf741f969f0702b13b8fb, two methods in
AbstractEmulatorMojo, writeEmulatorStartScriptUnix() and
writeEmulatorStartScriptWindows(), use
java.io.File.setExecutable(boolean) that had been introduced in 1.6.

But compiler and jar plugins still declare 1.5-compatibility. Fix this
by changing to 1.6.

Signed-off-by: Mykola Nikishov <78dc0cd3e7ef475d2c3e664078e5f1d7b3b719ab@mn.com.ua>

simpligility/android-maven-plugin,hgl888/android-maven-plugin,xiaojiaqiao/android-maven-plugin,Cha0sX/android-maven-plugin,ashutoshbhide/android-maven-plugin,Stuey86/android-maven-plugin,Stuey86/android-maven-plugin,greek1979/maven-android-plugin,psorobka/android-maven-plugin,CJstar/android-maven-plugin,CJstar/android-maven-plugin,mitchhentges/android-maven-plugin,kedzie/maven-android-plugin,Cha0sX/android-maven-plugin,xieningtao/android-maven-plugin,Cha0sX/android-maven-plugin,secondsun/maven-android-plugin,ashutoshbhide/android-maven-plugin,psorobka/android-maven-plugin,wskplho/android-maven-plugin,secondsun/maven-android-plugin,b-cuts/android-maven-plugin,xiaojiaqiao/android-maven-plugin,jdegroot/android-maven-plugin,secondsun/maven-android-plugin,WonderCsabo/maven-android-plugin,b-cuts/android-maven-plugin,kevinsawicki/maven-android-plugin,mitchhentges/android-maven-plugin,WonderCsabo/maven-android-plugin,jdegroot/android-maven-plugin,xieningtao/android-maven-plugin,greek1979/maven-android-plugin,repanda/android-maven-plugin,wskplho/android-maven-plugin,kedzie/maven-android-plugin,xiaojiaqiao/android-maven-plugin,hgl888/android-maven-plugin,repanda/android-maven-plugin