- we are ending sentences properly
- fixing of space issues
- fixed continuity issues in some sentences.

Reverts https://github.com/rails/rails/commit/8fc97d198ef31c1d7a4b9b849b96fc08a667fb02 .
This change reverts making sure we add '.' at end of deprecation sentences.
This is to keep sentences within Rails itself consistent and with a '.' at the end.