added roman conversion functions

- added roman conversion functions in the helpers
- added useRomanNumeralsForCenturyDisplay param to date time.conf
- added useRomanNumeralsForCenturyDisplay to getText function
Merge branch 'master' of https://github.com/collectiveaccess/providence into roman_century_dates
Added .DS_Store & .settings & .project to gitignore

Added .DS_Store & .settings & .project to gitignore
Added useRomanNumeralsForCenturies param allowing roman numbers like XXth century

Added useRomanNumeralsForCenturies param allowing roman numbers like XXth century
Updating function to treat roman numbers

Updating function to treat roman numbers
Allowing roman numbers in century expressions (XXth century)

Allowing roman numbers treatment in century expressions like "XXth century" if useRomanNumeralsForCenturies is set to true in datetime.conf
Correcting fonction presentation which had been copied/pasted to fast

Correcting fonction presentation which had been copied/pasted to fast
Merge pull request #15 from ideesculture/roman_century_dates

Roman century dates