This PRs updates java examples using the new Java API, by converting C++ examples to Java.
Examples CVC4Streams.java and PipedInput.java are removed since they are not longer supported by the API.
All examples are not included in the build which would be added in a future PR.
This PR updates the update-copyright.pl script to also update/add copyright headers to CMake specific files. It further fixes a small typo in the header.
Fixes#2846. One of the challenges of the Java bindings is that the
garbage collector can delete unused objects at any time in any order.
This is an issue with CVC4's API because we require all `Expr`s to be
deleted before the corresponding `ExprManager`. In the past, we were
using `NewGlobalRef`/`DeleteGlobalRef` on the wrapper object of
`ExprManager`. The problem is that we can have multiple instances of the
wrapper that internally all refer to the same `ExprManager`. This commit
implements a different approach where the Java wrappers hold an explicit
reference to the `ExprManager`. The commit also removes some unused or
unimportant API bits from the bindings.
