Fix to eliminate iconv for android (and other unix-es)

[ZGabrovski@gmail.com]

Test code - very simple - just call function

function Iconvert(S: string; var Res: string; const FromEncoding, ToEncoding: string): cint;
from iconvenc unit on button click.

Something like

uses iconvenc;
procedure testme;
var S : UnicodeString;
begin
Iconvert('dfsfsdf',S,'UTF8','UTF16')
end;

it is failed somewhere in iconv(H, nil, nil, @Dst, @Outlen);

But how to debug inside iconv?
Believe me I spent a hours to build the library with the same ndk version that I am using for my project.
The result is the same and the same.