Using {1}singular|]1,Inf[plural syntax does not include 0, negative number, nor decimal numbers between 0 and 1 (like 0.5), leading Symfony to throw an exception "Unable to choose..." if such number is tried on such translation string.

For many languages, the plural form would be acceptable for 0 and negative numbers, so it would be more resilient to use the syntax {1}singular|[-Inf,Inf]plural which means to use "singular" for 1 and "plural" for anything else.

Contributors can still submit better translations for specific languages as long as we keep a fallback form (with no selector), example:

']-Inf,-1[negative plural|{-1}minus one|{0}zero|{1}one|[-Inf,Inf]other'

The part about negative is only if those files get used independently, in the default context (using Symfony Translator) getPluralizationRule contains $number = abs($number);

Fix #53