libdvm interface tweaks/bugfixes

Signed-off-by: Jeremy C. Andrus <jeremya@cs.columbia.edu>
grab fread from real_libc (to be used later)

Signed-off-by: Jeremy C. Andrus <jeremya@cs.columbia.edu>
Compress log files

This patch enables the wrapped library to use libz (if available) to
compress all logfiles before writing them to disk. This uses a ton of
CPU cycles, but avoid costly I/O latency. The end result is a
semi-usable system when most of the libc entry points are wrapped!

	mkdir d/
	for i in *.gz; do gzip -d -c $i > d/${i%.gz}; done

Signed-off-by: Jeremy C. Andrus <jeremya@cs.columbia.edu>