Extraction is slow

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I'm trying out lib7zip for use in extracting images from CB7 archives for 
display on an ereader device.  It works correctly, but the performance is very 
slow compared to using libzip for CBZ or unrar's library for CBR.  I added some 
print statements to the C7ZipInStream::Read() method and see that the entire 
archive is read each time a single file is extracted.  Is it possible to speed 
this up within lib7zip by seeking to the correct location in the archive and 
only reading what is necessary?

Original issue reported on code.google.com by [email protected] on 2 Jan 2015 at 7:59