Allow the `actual` value to be a `template` about equalizer HOT 1 CLOSED

This issue is just too superficial. We should ask ourselves WHY we need such a feature.

And.. it appears that the answer is unclear. There may be some applications for such feature but, in most cases, it looks like its existence would suppose violation of the responsibilities segregation.

For example, we cannot have this line of code within a complex equalizer - this.Differentiate(x => x.Property, Value.Empty) - because it simply makes no sense. It demands the execution of assertions based on the expected value only and this is quite counterintuitive - as if this is not an equalization profile but some kind of a validation profile.

If there are some concrete scenarios that require the existence of the described feature, we shall re-open this issue and discuss it. Moreover, we have a candidate implementation in #52.

from equalizer.