iconv detected an illegal character in input string in xls column when using email as input

```
When parsing a excel column that contain data as like, some@mail.com.

then it shows 500 error with summary output.

but it solved using ,

function
Spreadsheet_Excel_Reader($file='',$store_extended_info=true,$outputEncoding='')
{
$this->_ole =& new OLERead();
$this->setUTFEncoder('UTF-8'); // newly added line

```

Original issue reported on code.google.com by `sivanth...@gmail.com` on 30 May 2015 at 7:01

Start in the Spreadsheet_Excel_Reader constructor and inspect how setUTFEncoder and OLERead handle XLS cell input. Reproduce the failure with an XLS column containing an email address and check the summary output. Done means the column parses without the iconv error or resulting 500 response.

Written by the indexing model from the issue text.