Support parsing dates in a few African languages

[rlskoeser]

Based on conversation with @Buzaabah

There are some historical African calendars in specific regions, but it would be more useful as a first step to support parsing contemporary dates in a few African languages, supporting day and month names in the target language and script.

We propose targeting these languages initially:

• Kinyarwanda - rw
• Ganda - lg
• Tigrinya - ti - written in Geʽez script

Some variant of each of these seems to be present in the python locale data already; let's start with that.

tasks

• generate localized dates in each of these languages; use each month and weekday at least once. @Buzaabah will review
• test parsing dates in these calendars with existing tools (python datetime, Babel) to determine how much of a gap there is
• start building out an undate parser using localized month/day names and abbreviations with these languages included