Built-in reusable components

More games are made with ACE. More elements are taken from old ones to new titles.

For me its quite good idea to collect all that snippets and add to ACE codebase, where all titlescan benefit from.

We have some options for that:

* put everything in already existing "generics" folder;
* put everything in "components" folder as inline code;
* put everything in "components" folder where all components would be git submodules.

For me, first option is actually best.