Create new test 112-nest.t

* Test fails, correctly.

Signed-off-by: Xiong Changnian <xiong-cpan@xuefang.com>
Renumber new test script.

* Based on 110-trace.t which really was a unit test.
* This is a feature test.

Signed-off-by: Xiong Changnian <xiong-cpan@xuefang.com>
Test passes.

* Error::Base POD fixed.

Signed-off-by: Xiong Changnian <xiong-cpan@xuefang.com>
All tests pass.

* Ship 410-nest.t
* Had to fiddle with a number of old tests;
	change -top to -nest, etc.
* Fix Cookbook.

Signed-off-by: Xiong Changnian <xiong-cpan@xuefang.com>
Merge branch 'feature-todo' into devel

Signed-off-by: Xiong Changnian <xiong-cpan@xuefang.com>