Clean up and support EPEL-5 builds
    
    - Drop -tests subpackage (general lack of interest in this), but include
      them as documentation for the main package
    - Don't need explicit runtime dependency on perl(Test::Builder::Module) if we
      have rpm ≥ 4.9 as it can auto-detect it
    - BR: at least version 0.61 of perl(Test::More) as per upstream
    - Drop unnecessary version requirement for perl(ExtUtils::MakeMaker)
    - Drop redundant %{?perl_default_filter}
    - BR: aspell-en rather than hunspell-en on old distributions where
      Test::Spelling uses aspell instead of hunspell
    - Don't BR: perl(Test::Perl::Critic) when bootstrapping
    - Don't use macros for commands
    - Don't need to remove empty directories from buildroot
    - Make %files list more explicit
    - Drop %defattr, redundant since rpm 4.4
    - Use tabs