Grammar/content fixes for email confirmation language

- account -> email address
- was -> has been
All other text does not use camel case
Missed some "instructions about" -> for
Fix typo in initializer template comment
Merge pull request #2912 from petervandenabeele/master

Fix typo in initializer template comment
Note that the cost of bcrypt grows dramatically with number of stretches

* this will avoid people (like me) loosing an hour trying to understand
  why doing it "a little bit safer" with 20 stretches suddenly takes
  60 seconds to do sign_up or sign_in. An example of such discussion is:
  http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/399627
Clarify that this stretch behavior is for bcrypt

* other encryptors show a different behavior regarding the
  number of stretches
Merge pull request #2913 from petervandenabeele/master

Note that the cost of bcrypt grows dramatically with number of stretches
Chase language changes in tests
WIP
Add a flag to views generator allowing user to specify which view directories to generate
Add a flag to views generator allowing user to specify which view directories to generate
add description to view generator flag
Rename variable to views, change flag to -v
Merge pull request #2916 from kayline/master

Add ability to generate only specified view directories
Add  README docs and a CHANGELOG entry for #2916
Bump mocha.
Update CHANGELOG.md with missing 2.1.x minor versions

Changelog for missing entries taken from https://github.com/plataformatec/devise/blob/v2.1.4/CHANGELOG.rdoc
Merge pull request #2933 from weimeng/update-changel

Update CHANGELOG.md with missing 2.1.x minor versions
Release v3.2.4