FIX for Date calculation

FIX for Date calculation

Rule :
- always format_date() before sending date to template
- always format_date_in_iso immediatly after reading a date coming from a parameter
- deal internally only with dates in iso

Note that :
- I could not test things related to issues stats due to the my DB -issues.issuedate not filled, see commit about 3.00.00.006
- acquisitions_stats does not work when you filter on date

Signed-off-by: Joshua Ferraro <jmf@liblime.com>