Respect user's timezone when comparing / parsing Dates
This patch replaces all occurrences of
Date.today always returns the date according to the server's local time zone, leading to all sorts of edge cases that occur more or less often depending on how large the offset between a user's timezone and the server timezone is. A test case illustrating the problem using
Issue#overdue? as an example is included.
The patch was extracted from Planio and also includes the changes proposed earlier by Holger Just in #20473, with the addition of two test cases to cover the date manipulation changes in