Use only zlib functions in trace.c that are available in the zlib shipped with R
Remove zlib.h inclusion from trace.h

When zlib.h is included in trace.h, the following inclusion chain
exists:

  Defn.h -> trace.h -> zlib.h -> zconf.h -> unistd.h

Since R defines many of its global variables by redefining "extern" to
an empty symbol and including Defn.h into main.c, this will declare
(among others) "char **environ" in main.c, overwriting the variable of
the same name from the C library. This causes a segmentation fault
when the tcltk library is loaded, e.g. when install.packages is
invoked.
Count inlined assignments in bc-compiled functions too
Add experimental peak cons counting

Add an experimental counter for determining the maximum number of at
one time. It is not yet sure if this count is accurate because it uses
another flag bit and it has not yet been verified if there are any
assignments of the full SEXPREC structure in R that would modify this
bit it outside of cons().
Merge branch 'master' into capture