Fix offset optimizing issue introduced by padding char (#398).
Force --svg-embed-bitmap on when user set --embed-image on.
Don't dump jpeg not in RGB or Gray colorspaces (Fix 400).
Update man page for --svg-embed-bitmap.
Merge pull request #407 from duanyao/fix_bitmap_dump

Fix bitmap dump
Merge pull request #406 from duanyao/fix_offset_and_padding

Fix offset optimizing issue introduced by padding char (#398).
Fix page box bug in DrawingTracer (#404); add more debug output.