Dublin

Features:

• Add list of day names and day_name function to French Republican converter
• Add multiple conversion methods to the French Republican calendar
• Add Dublin day count and Julian day count converters
• Add month names to Bahai and Hebrew calendars.

Other changes:

• Clarify that weekdays run Monday=0 to Sunday=6 (#1)
• Change Julian converter to use astronomical notation (0 = 1 BCE, -1 = 1 BCE)
• Expanded tests