[ticket/12721] Add Generic.Files.LowercasedFilename in the legacy ruleset

PHPBB3-12721
[ticket/12721] Add Squiz.Arrays.ArrayBracketSpacing in the legacy ruleset

PHPBB3-12721
[ticket/12721] Add Generic.Functions.OpeningFunctionBraceBsdAllman

PHPBB3-12721
[ticket/12721] Add Squiz.ControlStructures.ElseIfDeclaration in legacy

PHPBB3-12721
[ticket/12721] Add Squiz.ControlStructures.ForEachLoopDeclaration

PHPBB3-12721
[ticket/12721] Add Squiz.ControlStructures.ForLoopDeclaration in legacy

PHPBB3-12721
[ticket/12721] Add Squiz.Functions.LowercaseFunctionKeywords in legacy

PHPBB3-12721
[ticket/12721] Add Generic.NamingConventions.ConstructorName in strict

PHPBB3-12721
[ticket/12721] Update rules descriptions

PHPBB3-12721
Merge pull request #2603 from Nicofuma/ticket/12721

[ticket/12721] Improve the code sniffer: simple rules

* Nicofuma/ticket/12721:
  [ticket/12721] Update rules descriptions
  [ticket/12721] Add Generic.NamingConventions.ConstructorName in strict
  [ticket/12721] Add Squiz.Functions.LowercaseFunctionKeywords in legacy
  [ticket/12721] Add Squiz.ControlStructures.ForLoopDeclaration in legacy
  [ticket/12721] Add Squiz.ControlStructures.ForEachLoopDeclaration
  [ticket/12721] Add Squiz.ControlStructures.ElseIfDeclaration in legacy
  [ticket/12721] Add Generic.Functions.OpeningFunctionBraceBsdAllman
  [ticket/12721] Add Squiz.Arrays.ArrayBracketSpacing in the legacy ruleset
  [ticket/12721] Add Generic.Files.LowercasedFilename in the legacy ruleset
Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/12721] Update rules descriptions
  [ticket/12721] Add Generic.NamingConventions.ConstructorName in strict
  [ticket/12721] Add Squiz.Functions.LowercaseFunctionKeywords in legacy
  [ticket/12721] Add Squiz.ControlStructures.ForLoopDeclaration in legacy
  [ticket/12721] Add Squiz.ControlStructures.ForEachLoopDeclaration
  [ticket/12721] Add Squiz.ControlStructures.ElseIfDeclaration in legacy
  [ticket/12721] Add Generic.Functions.OpeningFunctionBraceBsdAllman
  [ticket/12721] Add Squiz.Arrays.ArrayBracketSpacing in the legacy ruleset
  [ticket/12721] Add Generic.Files.LowercasedFilename in the legacy ruleset