Change Java to use array indexes instead of methods

Method invocations are not entirely free on Android. Change the
generated Java code to use the same array-based approach used in
JS and C to compute dimensions, positions, etc instead of relying
too heavily on method invovations. As a bonus, the Java transpiler
becomes a lot simpler because the code is more analogous to the C
counterpart.

In my local benchmarks this change gives us a major performance
boost on Android (between 15% and 30%) depending on the device
and the runtime (Dalvik|Art).

src/transpile.js

@@ -261,6 +261,7 @@ function transpileAnnotatedJStoC(jsCode) {
     .replace(/node\./g, 'node->')
     .replace(/child\./g, 'child->')
     .replace(/parent\./g, 'parent->')
+    .replace(/var\/\*\(c\)!([^*]+)\*\//g, '$1')
     .replace(/var\/\*([^\/]+)\*\//g, '$1')
     .replace(/ === /g, ' == ')
     .replace(/ !== /g, ' != ')