Fix windows VS builds.

Fix broken solution file and add project entries for new files.
Flush pending text on a change of CTM.

Without this, comparefiles/Bug695086 renders the barcode test upside
down.
Bug 695183: Inflate large buffers at a time for speed.

When I changed the stream implementations to use implementation
specific buffers, rather than a generic public one in every fz_stream,
I changed fz_read_byte to only get a single byte at a time.

I noted at the time that the underlying stream was free to decode
larger blocks if it wanted too, but I forgot to actually do this for
the flate decoder. Fixing this here should solve the speed issues.