tools: Fix dtnoutbox / dtninbox

BLOB were opened on each write access and the put pointer was resetted each time and files are always <=  10k. BLOB access is now done in the main() method.

Silly static variables removed and replaced by local variables
Many string replaced by ibrcommon::File class
Missing initializations of variables added
Error in TarUtils now throw an exception
Code style: Double spaces removed and indentation fixed