Don't write one file many times into resource

If you put this same files twice file should be visible in resources twice, but I don't any good reason for putting file's content twice.

Example:

<!DOCTYPE RCC><RCC version="1.0">
<qresource> 
<file alias="aaa">000</file>
<file alias="bbb">000</file>
</qresource>
</RCC>

Here's the patch. I use the same offset to blob in resource for this same file (when RCCFileInfo-s have the same m_fileInfo.absoluteFilePath() ).