p5-XML-SAX non-interactive patch proposal

[milki]

The p5-XML-SAX-0.99 includes an interactive prompt on package install.
The attached patch moves that choice into an OPTIONs. It also removed
ParserDetails.ini from the pkg-list. This does not deal with the issues
with p5-XML-SAX-Base.

>From a glance, it appears that ParserDetails.ini lists available parsers
for XML::SAX. This interactive option allows the user to update the
XML::SAX::PurePerl entry in the file.

Note: There are still issues with how this ParsersDetails.ini is
updated/created which I open to others to fix...

Basically:
- If XML::SAX has already been installed, there should be an existing
  ParsersDetails.ini. The port install should update the file.
- Otherwise,
  - The file might exist anyways in @INC, in which case it should be
    updated
  - Else, it should be created

If the port is freshly installed out of PREFIX, the install will fail
because it won't find XML::SAX in @INC (running port test).
If the port is installed (different PREFIX) side-by-side an existing install,
the existing ParsersDetail.ini will be updated instead of creating a new one
in the different PREFIX.

-- 
milki