Description:
------------
When trying to create multiple font faces from the same font file Cairo will 
throw the following exception 

Fatal error: Uncaught exception 'CairoException' with message 
'CairoFtFontFace::__construct(): An error occurred opening the file' in 
/root/test.php:5
Stack trace:
#0 /root/test.php(5): CairoFtFontFace->__construct('/root/DroidSans...')
#1 {main}
  thrown in /root/test.php on line 5

Test script:
---------------
<?

$cairo =  new CairoFtFontFace( "/root/DroidSansMono.ttf" );
print_r($cairo); 
$cairo =  new CairoFtFontFace( "/root/DroidSansMono.ttf" );
print_r($cairo); 

?>

Expected result:
----------------
two CairoFtFontFace Objects should be created 

Actual result:
--------------
One object is created and the second invocation throws an exception 

CairoFtFontFace Object
(
)
Fatal error: Uncaught exception 'CairoException' with message 
'CairoFtFontFace::__construct(): An error occurred opening the file' in 
/root/test.php:5
Stack trace:
#0 /root/test.php(5): CairoFtFontFace->__construct('/root/DroidSans...')
#1 {main}
  thrown in /root/test.php on line 5