Adder and remover sidenote

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets | none

There are cases when you only want either adder or remover, important to know both of them need to be found if any is to work.
Merging emphasized notes

Merged both notes into one, in accordance to discussion feedback.
Update form_customization.rst

In the Form chapter of Book for Symphony 2.3, we use '{{ form(form) }}' to render the entire form ( in contrast to '{{ form_widget(form) }}' for older version of Symfony ). so maybe it should use '{{ form(form) }}' here for consistency.
Applied suggestion by Ryan
Update slash_in_parameter.rst

"name" in requirements is confusing, I had problem for doing the same and then after 2 days I found that the "name" should be same as the parameter, it is not part of symfony config

   requirements: 
        name: .+
Changed userName to username
Improved naming
Added a little sample on Option uses with "spaces"
[WIP] - Console add Console arguments page
use the C lexer for Varnish config examples
Fix typos in code
Removed parameters from service
Apply a grammatical improvement

I think the "each the" form is not correct in English, as "each" must
generally be used as in "each one of", or "each of".
finish #3744
Completely re-reading the controller chapter
update best practices index

This way, the table of contents on the index page has only one level
like every other index in the documentation.
array options need array default values
remove unused label
remove semicolons in PHP templates
Fix typo: Objected => Object