Fixed find_perl_interpreter() so we can find the perl executable
when running from uninstalled perl even when $^X contains a
relative path. [Yitzchak Scott-Thoennes]Fixed warning message where we were printing the wrong field names.
[Chris Dolan]Added a 'testpodcoverage' action that runs a POD coverage check for
all modules in the distribution. [Yanick Champoux]Added a Cookbook example of subclassing to modify an action. [Dylan
Martin and David Golden]When building HTML documentation, we were opening the POD file and
not checking whether the open succeeded, which of course caused
problems down the line if it failed. Now we do "or die(...)" like
everywhere else. [Spotted by Joerg Braun]