Make sure Pako always has enough room

Make sure Pako always has enough room

Previously, we used a fixed chunkSize of 100KiB for Pako's output
buffer.  Using a hardcoded size caused issues, since Pako would assume
we wanted to use multiple chunks, and we didn't deal with this.  Now,
`Inflator#inflate()` takes a new `expected` argument, which indicates
the expected output size.  If this is bigger than the current chunkSize,
Inflator allocates a new output buffer that's big enough to hold the
output.

Fixes #531