Velocity Code Style

Velocity scripts must follow these rules:

• Use 2 spaces for indentation
• Use single quotes for strings that don't need to be parsed/interpreted. This improves performances.
• Always capture the result of a method call in a variable to avoid side effects (things output to the result: what the method returns or unwanted empty lines). For example:
  #set ($discard = $someVar.someMethod())
• Internal macros that are not aiming at being exposed as API should always be prefixed with the character _. API macros should always be properly documented with information on the parameters and a since information. This rule has been introduced with XWiki 15.10RC1 so old macros don't rely on it: they are considered by default as APIs but can be renamed after a vote.