BUGS:
	- Tree editing is incorrect when editing non-root elements
	- Stream load/save not implemented
	- Binary streams not properly handled (See hex editor in FEATURES)
	- No item deletion
	- No key name editing for dictionaries
	- No indirect object creation
	- Simple data edits (ie non-structural) may not take account of aliasing

FEATURES:
	- Edit in PDF syntax or decoded text form for strings, names
	- Hex editor for streams
	- Search for objects by type, value. Must handle reference cycles.
	- Related to above, find list of all objects that reference a given
	  indirect object, present by tabbing list open for all references,
	  highlighting referencing cells (nodes need highlight flag?)
	- Enumerate and jump to interesting structures in PDF like fonts,
	  images, pages, etc.
	- Image browser/thumbnailer with save image and replace image operations
	- Font extraction and replacement
	- Search for text in content streams
	- Force load all objects (as non-modal task with status bar progress)
	- Flat mode where references not followed, tree is rooted at table
	  of indirect objects. Like old browser. Support switching between
	  flat and /Catalog-rooted view using model changes. Two views
	  with two models not practical because of aliasing issues (or maybe
	  _do_ keep two models and have shared alias map?)
	- "Clone unique" for multiply-referenced indirect objects
	- Cycle-friendly counting of references to indirect objects so user
	  can tell multiply-referenced vs unique

FUTURE:
	- PoDoFoPdfInfo integrated in GUI
	- "Check PDF" (very simple PDF validation - should be Qt independent
	  and use underlying document not our model implementation).
	- GUI support for doc merge, page insert, page extract, etc.
