Since many different rotation or general transforms may used for a glyph
during animation scenarios, we should be caching these more weakly to
faster reclaim native and Java heap. Presently we use Soft references
which are reclaimed only when the heap cannot be expanded.
There is of course a trade off against performance as subsequent uses
may exist and if they come after a GC, we need to re-create the glyph.
However in testing this seems acceptable given the potential benefit to
more stable memory use. And the reduced GC load actually helps performance in
high memory usage scenarios.