Use dynamic allocated buffers instead static buffers. No member or
line length limit anymore - now 500 members or 5000 members are
possible. For security group lines longer than 256K will be count as
an error. 256K should be enough for 65536 users.

Support comments (lines that begin with a #) if compiled with
option -DGROUP_IGNORE_COMMENTS.

Fortunately it seems that all system utilities which use getgrent()
functions are dynamically linked executables. So you need only
rebuild libc.so.3.0 if you want this change. Note: if you have
an old X server which depend on libc.so.2.* you should rebuild
libc.so.2.* too.

Not a 2.2 candidate.