Improvements on #102

In #102, there was 2 issue left:

* the status description is too long to be posted, as reported at https://github.com/numenta/nupic.tools/pull/102#issuecomment-46981619
* should fix #103

This PR fixes these 2 problems. The wording is now more concise:

> NuPIC Status: Please merge `numenta:master` into `utensil:testing-non-mergeable-pr` and resolve merge conflicts.

This wording is 111 characters long and unless the branch name is insanely long, it would not go beyond the 140-character restriction.