OpenSystemsDevelopment / qpdf

Also, delay adjustments for compressed objects until needed by
linearization checks.

Also, remove redundant clearing of the xref tabl during QPDF destruction.

Manual edits for cases not handled by search and replace

Using search and replace.

For consistency with similar methods, e.g. replaceObject.

Also, change test for QPDFObjGen::isIndirect to obj != 0.
Delete comment from commit afd35f9.

Change method signatures to use QPDFObjGen.
Use QPDFObjGen methods where possible.
Remove redundant QPDF::objGenToIndirect.

Change method signature to use QPDFObjGen.

Change method signature to use QPDFObjGen.

Rather than using object id -1 to mean "don't care", use object ID 0,
and clarify the difference between that use and indication of a direct
object.

Remove variables obsoleted by commit 4f24617.

Where not possible, use "auto" to get the iterator type.

Editorial note: I have avoid this change for a long time because of
not wanting to make gratuitous changes to version history, which can
obscure when certain changes were made, but with having recently
touched every single file to apply automatic code formatting and with
making several broad changes to the API, I decided it was time to take
the plunge and get rid of the older (pre-C++11) verbose iterator
syntax. The new code is just easier to read and understand, and in
many cases, it will be more effecient as fewer temporary copies are
being made.

m-holger, if you're reading, you can see that I've finally come
around. :-)