[TW-1395] Capitalization is not applied to letters with diacritics

_Jeremy John Reeder on 2014-08-19T17:17:51Z says:_

There are parts of TaskWarrior that convert text to "proper" case. That is, they capitalize the first letter. Well, this seems to only work for letters which do not have diacritics. If a day of the week starts with `ĵ` (lowercase `j` with circumflex), then `task calendar` leaves it as `ĵ` when it should convert it to `J`. This results in a set of headings with inconsistent case, such as `Di Lu Ma Me ĵa Ve Sa` in the case of the Esperanto language. This issue probably applies equally to any other case-altered localized string that starts with any character other than [a-z], such as the Spanish `é`, the French `ç`, or even the German `ß`.