Warn and auto-wrap $expected in meta_path_deeply to avoid bugs.

For example, kentnl/Dist-Zilla-Plugin-Prereqs-MatchInstalled#3
v1.003002

 [00 Bugfix]
 - Warn and auto-wrap $expected in meta_path_deeply to avoid other instances of
   kentnl/Dist-Zilla-Plugin-Prereqs-MatchInstalled#3

 [Dependencies::Stats]
 - Dependencies changed since 1.003001, see misc/*.deps* for details
 - develop: (suggests: ↑1)
 - runtime: (recommends: ↑1)
 - test: (recommends: ↑1)
post-release cleanup