Testing whether or not the build platform has a working iconv

[Richard Sharpe]

So,

I have some changes that allow configure to correctly find the include 
file and library for iconv.

However, I notice that the test to see if we have a working iconv, there 
are two problems:

1. It assumes that iconv uses the standard include files and library 
names.

2. It tests for ASCII to UCS-2LE as a conversion type, which Samba handles 
internally, and iconv-2.0_3 on FreeBSD and the version of iconv on 
Slowaris does not seem to handle these. A better test would be for CP850 
to UCS-2LE, I think.

Any observations?
 
Regards
-----
Richard Sharpe, rsharpe[at]ns.aus.com, rsharpe[at]samba.org, 
sharpe[at]ethereal.com, http://www.richardsharpe.com