Refactored some attributes to make it easier to understand what they mean.

added ability to set subtitle text below the week-day title text.
Demonstrated in WholeViewSnappingActivity.
replaced deprecated clipRect function with the more recommended one, as written here: https://stackoverflow.com/q/50231950/878126

Author: AndroidDeveloperLB

library/src/main/java/com/alamkanak/weekview/WeekDaySubtitleInterpreter.kt

@@ -0,0 +1,7 @@
+package com.alamkanak.weekview
+
+import java.util.*
+
+interface WeekDaySubtitleInterpreter {
+    fun interpretDate(date: Calendar): String
+}