Negative values, placeholder fix and French update!

Improvements:

• Negative money, experience, max health and max oxygen rewards are now possible, e.g. IncreaseMaxHealth: -2.
• Negative values can now be used for the /aach add command, e.g. /aach add -10 DistanceFoot DarkPyves.

Bug fix:

• The aach_playedtime placeholder will now be displayed in hours, similarly to /aach list.

Translations:

• Updated French translation, thanks to @Achent007 for his contribution!