netpgp: fix indentation in Lua binding example program

netpgp: fail if the shared library cannot be loaded

The secret key is required for decryption and signing. Indicate it by setting
the "need seckey" variable before calling init.

sign_file function expects 5 parameters, include the output filename.

Use LD_LIBRARY_PATH to manage the library path, and don't try to second
guess from the lua driver program

Use a lua for loop in preference to a while and increment in the lua
example code - suggested by Marc Balmer.

% make USETOOLS=no t
cp Makefile a
./netpgp.lua --sign --detached a
netpgp: default

Use a lua for loop in preference to a while and increment in the lua
example code - suggested by Marc Balmer.

% make USETOOLS=no t
cp Makefile a
./netpgp.lua --sign --detached a
netpgp: default key set to "C0596823"
pub 2048/RSA (Encrypt or Sign) 1b68dcfcc0596823 2004-01-12
Key fingerprint: d415 9deb 336d e4cc cdfa 00cd 1b68 dcfc c059 6823
uid Alistair Crooks <agc@netbsd.org>
uid Alistair Crooks <agc@pkgsrc.org>
uid Alistair Crooks <agc@alistaircrooks.com>
uid Alistair Crooks <alistair@hockley-crooks.com>
netpgp passphrase:
-rw-r--r-- 1 agc agc 287 Oct 17 15:58 a.sig
./netpgp.lua --verify a.sig
netpgp: default key set to "C0596823"
netpgp: assuming signed data in "a"
Good signature for a.sig made Sat Oct 17 15:58:09 2009
using RSA (Encrypt or Sign) key 1b68dcfcc0596823
pub 2048/RSA (Encrypt or Sign) 1b68dcfcc0596823 2004-01-12
Key fingerprint: d415 9deb 336d e4cc cdfa 00cd 1b68 dcfc c059 6823
uid Alistair Crooks <alistair@hockley-crooks.com>
uid Alistair Crooks <agc@pkgsrc.org>
uid Alistair Crooks <agc@netbsd.org>
uid Alistair Crooks <agc@alistaircrooks.com>
%

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Minor changes to find lua glue library, and to set the home directory on
the correct C/Lua structure

Add lua language bindings for netpgp