title: Char vs unsigned char for byte arrays
body: <p>When storing "byte arrays" (blobs...) is it better to use <code>char</code> or <code>unsigned char</code> for the items (<code>unsigned char</code> a.k.a. <code>uint8_t</code>)? (Standard says that <code>sizeof</code> of both is precisely 1 Byte.)</p>
  
  <p>Does it matter at all? Or one is more convenient or prevalent than the other? Maybe, what libraries like Boost do use?</p>