Need cleaner granularity on Symbol tables and headers

[KarlSchimpf]

To generalize the decompressor reader, we need multiple copies of default (algorithm) symbol tables. Currently, this isn't possible.

Either we should add a "copy" symbol table method, or modify the "root" install methods to allow us to update the default copy.

Another approach is to realize that for the decompressor, we only need header built so that we can choose the algorithm to apply. Once the algorithm is known, we can load on demand as needed. This solution will remove the need for copying the default algorithm, since it will be loaded (on demand) for as many casses as it is needed.