Test.pl wrapper for is, isnt, like ...

[atoomic]

similar to what we use in blead we should use a custom library that provides the basic test functions like is, isnt, like...

from #128

...in order to maintain compatibility with perls < 5.6. However, we could write our own is, isnt, like functions in a local library (wrapping Test::ok) that provide the same APIs as Test::More's functions, to make it easier to write (and read) the tests.

[khwilliamson]

This is now done in 3.56