Does not run on Java 9

[islandsvinur]

When starting on macOS with early access build of Java 9 installed, the "9-ea" version string is not recognised.

Exception in thread "main" java.lang.NumberFormatException: For input string: "9-ea"
	at java.base/java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
	at java.base/java.lang.Integer.parseInt(Integer.java:695)
	at java.base/java.lang.Integer.parseInt(Integer.java:813)
	at ika.utils.Sys.isMacOSX_10_5_orHigherWithJava5(Sys.java:149)
	at ika.app.Main.main(Main.java:41)