Enable custom patterns

[Blackjacx]

Actual behaviour

Right now one project that uses SHDateFormatter has a format that defines a special order of date components in SHDateformatter+Extensions.swift, like:

let weekdayString = string(from: date, format: .shortWeekday, timeZone: timeZone)
let dateString = string(from: date, format: .noTimeShortDateNoYear, timeZone: timeZone)
let timeString = string(from: date, format: .shortTimeNoDate, timeZone: timeZone)
return weekdayString + ", " + dateString + " - " + timeString

This doesn't work in other languages like Arabic.

Expected behaviour

For these cases Apple has defined a method that uses template date format strings and changes (reorders) them for the specified language. To make that work we have to either add a custom date format to SHDateFormatter which takes a string OR put that special date format in the enum and handle the custom format in SHDateFormatter, like:

SHDateFormatter/Source/SHDateFormatter/Classes/SHDateFormatter.swift

Lines 58 to 62 in 33b6741

	case .shortWeekday, .longWeekday, .shortMonth, .longMonth, .longYear, .shortYear, .noTimeShortDateNoYear,
	.shortYearMonth, .longYearMonth:
	SHDateFormatter.formatter.dateFormat = DateFormatter.dateFormat(fromTemplate: format.rawValue,
	options: 0,
	locale: locale)

I guess the latter is the better option!

Don't forget to update the tests…