Fix installations using Carton or Carmel

[doojonio]

Hello. Looks like it's impossible to install this module using Carton.
We're going to start using Carton in our workflows, but we faced the following problem:

! Couldn't find module or a distribution PDF::Builder (3.021)
Successfully installed Class-Accessor-0.51
! Installing the dependencies failed: Module 'PDF::Builder' is not installed
! Bailing out the installation for PDF-TextBlock-0.13.

We're using PDF::API2 inside our application and when PDF::TextBlock is going to be installed earlier PDF::API2 it tries to install PDF::Builder because of behavior defined in Makefile.PL. I think it's better for everyone to remove this code and if someone will forget to install PDF::API2 or PDF::Builder i'm sure he will know about this very soon.

As I can see from code inside PDF::TextBlock module it will not cause any compilation time errors related to PDF::API2 or PDF::Builder modules because there is no explicit use or require statements inside packages.

[jhannah-mm]

hmm @PhilterPaper can you look at this please? I think you added (#7) the code they're suggesting be removed?

[PhilterPaper]

I'm not clear on what you're seeing. It is supposed to first check whether PDF::API2 is installed, and if so, use it (don't bother installing PDF::Builder). If it's not, see if PDF::Builder is installed, and if so, use it instead (don't bother installing PDF::API2). If neither is installed, the default choice is PDF::Builder. Do you have neither installed, and you want 1) to default to PDF::API2 instead, and 2) PDF::Builder is unavailable anyway for some reason on this system? Any chance of forcing a PDF::API2 install before trying to install PDF::TextBlock? Otherwise, any way to feed a desired choice to Makefile.PL (i.e., on the command line) to override the default choice, or look for some sort of configuration file or environment variable?

As I recall, the original system was hard coded to install PDF::API2, so I added some flexibility to use one or the other, as found. At installation time, if neither was present, PDF::Builder would be installed by default. I suppose that for systems which won't allow PDF::Builder, that might be an issue.