Fix Mime Type Helper on Multiple Extensions
Fix Mime Type Helper on Multiple Extensions

Fix mime type helper on multiple extensions for the same mime type.
Previously if there were multiple extensions the last one would be the
only one

- Reverse mime type array
- Flip methods
- Add phpdoc


Former-commit-id: 8fd6c78dc0f0b2110b389d01e2752365465b7a6a
jaromirdalecky/concrete5,mainio/concrete5,jaromirdalecky/concrete5,biplobice/concrete5,mainio/concrete5,MrKarlDilkington/concrete5,triplei/concrete5-8,haeflimi/concrete5,a3020/concrete5,MrKarlDilkington/concrete5,mlocati/concrete5,KorvinSzanto/concrete5,triplei/concrete5-8,hissy/concrete5,hissy/concrete5,jaromirdalecky/concrete5,deek87/concrete5,olsgreen/concrete5,acliss19xx/concrete5,KorvinSzanto/concrete5,KorvinSzanto/concrete5,biplobice/concrete5,olsgreen/concrete5,olsgreen/concrete5,mlocati/concrete5,deek87/concrete5,deek87/concrete5,mlocati/concrete5,hissy/concrete5,haeflimi/concrete5,MrKarlDilkington/concrete5,mainio/concrete5,rikzuiderlicht/concrete5,concrete5/concrete5,acliss19xx/concrete5,biplobice/concrete5,acliss19xx/concrete5,haeflimi/concrete5,triplei/concrete5-8,concrete5/concrete5,concrete5/concrete5,hissy/concrete5,mlocati/concrete5,rikzuiderlicht/concrete5,biplobice/concrete5,a3020/concrete5,concrete5/concrete5,jaromirdalecky/concrete5,deek87/concrete5,rikzuiderlicht/concrete5,haeflimi/concrete5