Add multidex support

[10MINT]

I'm running into some issues because I need too much jar files for my extension. The error I'm getting is

[java] trouble writing output: Too many method references to fit in one dex file: 126456; max is 65536.
[java] You may try using multi-dex. If multi-dex is enabled then the list of classes for the main dex list is too large.

Somebody mentioned a solution here
https://community.appinventor.mit.edu/t/how-to-add-multidex-support-to-appinventor/257

[ewpatton]

It should be easy enough to add the multidex flag to build.xml invocation of dx, but the problem is that App Inventor's build system doesn't expect that there will be more than one classes.dex in the extension. You may want to look at the dependency tree of your extension and see if all the dependencies are really necessary to do what you want. The number of methods in your extension exceeds the number of methods in all of App Inventor and its dependencies...

[10MINT]

I know that I use a lot of jar files, but that's because AI doesn't support dependency resolving. I have to resolve all dependencies and add all jar files to lib/deps. Would splitting the methods into different extension help to overcome the limit?

[ewpatton]

If App Inventor resolved the dependencies, it wouldn't fix the problem of there being too many dependencies. This simply won't work unless we patch core to support extensions having more than one classes.dex file.

[pavi2410]

I have to resolve all dependencies and add all jar files to lib/deps

@10MINT Does the dependencies here refer to those used by App Inventor itself? Doesn't AndroidRuntime.jar have them?

[10MINT]

@pavi2410 I meant external dependencies. For example, the Apache POI library has a lot of dependencies