catch errors and warnings given by ppi

[szabgab]

Recently I got this on the console:

 Illegal parse state in 'foreach' type compound statement at /home/gabor/perl5lib/lib/PPI/Lexer.pm line 810.

It is indeed a warn() call in PPI but as I can see there are also die() calls and warn() calls.
We should wrap the whole ppi processor to catch all these warnings and errors, save the file that was parsed in a separate file and report the error so we can build test cases for PPI with those files
or code snippets.