This patch updates the main graphics/podofo port to the newer 0.10.0 version, while keeping the previous version as graphics/podofo09.
The new version is API/ABI incompatible, so the old version needs to be kept for compatibility.
I've modified the 0.9.x version port so it can be installed concurrently with version 0.10.0 and modified all ports depending on it to use the old port.
I have not modified the deskutils/calibre port, because I plan to update it at the same time of this commit to the latest version which depends on podofo 0.10.0.
I have create no UPDATING entry because I think all the tools we provide to manage ports or packages should be able to do "the right thing" automatically in this case.
Also, note that the commit messages that appear in this review are just placeholders, I'll choose better and more descriptive wording for them at commit time.