Update forms.rst

Accessing form values via `vars` property instead of getter. Updated PHP templating examples.
Update forms.rst

Accessing form values via `vars` property instead of getter. Updated PHP templating examples.
merge
Fixed vars as object property, not array
Fixed broken urls
Documented the Change the Default Command in the Console component
Added the version number where the setDefaultCommand was introduced
Added the delete document to avoid broken urls and added a notice that
the document was moved to another location
Changed the code to remove references to Symfony Framework since it's
the standalone component
Updated references to the new document
Moved `versionadded` to the right section
Merge pull request #3424 from danielcsgomes/fix_broken_urls

Fixed broken urls
[#3424] Backporting a change to 2.3
Merge branch '2.3' into 2.4
Applied some suggestions
syntax error corrected
add default value to mapped option of entity
document auto_initialize overriden option
[#3407] Re-wording things so that people don't pay too much attention to auto_initialize
Use static Request methods in Trusting Proxies doc

As these methods manipulate static properties, it makes sense to use the static methods. This also means that we don't need to create a throwaway Request instance just to set the trusted proxies.