Text changes for some responses

Some of the negative matcher messages are not idiomatic English.

* Changed 'Not expected FOO to BAR' to 'Expected FOO not to BAR'
* Changed 'Not expected FOO' to 'Did not expect FOO'
* Changed 'FOO not expected to BAR, but it is' to 'FOO not expected to BAR, but it did'

This change has the disadvantage that the negative responses are now not as similar to the positive ones, and the "Not" is later in the text, but they do sound more correct to a native speaker.