Revisit tests

[joachimmetz]

• revisit test plan
• valgrind tests
• fix test failing on Cygwin
  • glob test not finishing (horribly slow on Cygwin - skip for now on Cygwin, until faster version)
• fix test failing on MinGW-MSYS
  • glob test failing
  • fix sed: -e expression #1, char 9: unterminated `s' command
• afl tests - now covered by OSSFuzz
• check / fix prefix in test scripts
• Add bounds tests
  • number of segment files
  • max supported input size
• single threaded and multi threaded tools tests
• re-add interactive mode for tools tests
• pyewf write test
• improve performance of glob test to run on Cygwin
• speed comparison tests
  • /dev/urandom using dd and ewfacquire
  • /dev/zero using dd and ewfacquire