Modify PDF operators.

  1 Depart Process:
  2 1. Grep xref and trailer binary position in file.
  3 2. Dump xref table and trailer part.
  4 3. Calculate every object binary offset and length.
  5 4. Dump every object.
  6 5. Dump header part.
  7
  8 Manual Process:
  9 1. Find object contains stream.
 10 2. Deflate stream.
 11 3. Modify grahics operators.
 12 4. Flate stream back to object.
 13
 14 Part Process:
 15 1. DD header part.
 16 2. DD every object, log every binary offset.
 17 3. Rewrite xref table.
 18 4. Rewrite trailer part.