Allow tables to be resized and accessed as FloatBuffers

These functions expose additional functionality to the Java domain. Tables may be resized. And instead of reading and writing to them via a Java-array intermediary, they may now be accessed directly as `java.nio.FloatBuffer`s. Finally, the ability to execute a generic `Runnable` in a thread-safe way has been added, ensuring that the audio thread is not running.
What will happen if Pd has to reallocate the array? Will the byte buffer remain valid or would this put us in a situation where method invocations on the buffer become unsafe? That would be a deviation from the general spirit of PdBase (and Java, too).