fix(achievements): Differentiate singular and plural

Allows Streak and Perfect Day achievements to dynamically show a singular or plural version of their text based on how many achievements the viewed profile has stacked.

BREAKING CHANGE: Will lead to 'string not found' errors until the singular version strings are implemented in all locales on habitrpg-shared.
fix(achievements): correct malformed Angular
Merge branch 'sabe/achievements' of https://github.com/HabitRPG/habitrpg.git into sabe/achievements

Conflicts:
	views/shared/profiles/achievements.jade