V0.4.1 adds a few bug fixes, a few more user examples, internal refactoring and some performance
improvements.

Bug fixes:
19116 When an exception is thrown during advice execution, the error message always reports the advice type is :before!
19261 after_raising DSL method provides no way to specify exceptions

Enhancements:
18705 Remove duplication and complexity in options-handling code
19320 Move the Aquarium::...::AspectDSL file to Aquarium::DSL for convenience
19399 Improve the Design by Contract example

I added a new :exceptions argument (synonym :exception) that takes a single exception or list thereof.
You can only use this argument with :after_raising. If you specify exceptions with the latter and use
the :exceptions argument, the values will be merged.

I thought it was ugly to have to type "include Aquarium::Aspects::DSL::AspectDSL", so I moved the code so
now it's "include Aquarium::DSL". However, for backwards compatibility, the old module still works.