Converting from PDF::API2 to PDF::Builder

If you have been running PDF-creation code under PDF::API2, and wish to give
PDF::Builder a try, for the most part it should be quite compatible. It is a 
superset of PDF::API2 functionality, but there could be some "gotchas" if your
code made use of certain obsolete things.

For most code, simply changing all occurences of "PDF::API2" to "PDF::Builder"
in the code should be sufficient to start running under PDF::Builder. If you
get errors reported by Perl, check the following two files:

* INFO/DEPRECATED is a list of DEPRECATED method names, etc. that have been
  removed or changed, or will be in the future. We give at least 2 years' 
  notice of such items, as well as how to change your code to avoid problems.
  Whether or not you have used PDF::API2, you should periodically check in
  with this file to see if there are any upcoming changes you need to prepare
  for.

* INFO/KNOWN_INCOMPAT is a list of known incompatibilities between PDF::API2
  and PDF::Builder. Most are minor differences in behavior introduced as bugs
  were fixed over time. A few times, code was changed to match the 
  documentation (such as order of arguments). We try hard to avoid changing 
  existing code behavior, but sometimes it's just not possible, particularly 
  if the old behavior was actually in error!

Note that PDF::Builder is *NOT* a layer over PDF::API2 (i.e., does not
require that PDF::API2 be installed). It is a totally independent installation.
It is quite possible to install *BOTH* at the same time; they will not 
interfere with each other's operation. This allows PDF::API2 users to avoid
going offline while testing a switchover to PDF::Builder.