include config.h in hconfig.h in order to make use of defines set by the
configure script
gzopen returns a gzFile type which in turn already is a pointer to
struct gzFile_s
typo
another instance of the gzFile vs struct gzFile_s confusion
make use of the format specifier PRIu64 for printing uin64_t values
remove unused variables
consider div-by-0 when calculating the vcache's hitrate
wrap the progress bar in a critical region