[l2h] netpbm for Solaris (5.7)

[Graham Gough]

I'm a happy l2h user on my Linux box, but am trying to install it for
others on a Solaris machine. I'm having some problems building
netpbm using xmkmf. Make Makefiles fails with 

making Makefiles in ./libtiff...
        mv Makefile Makefile.bak
making Makefiles in ./pbm...
/bin/sh: ./pbm: does not exist

No doubt I could sort this mess out if I tried long enough, but has
anyone else been down the same track before and come across similar
problems.

Graham