• Fix retention and rotation issues when file sink initiliazed with delay=True (#113).
• Fix "sec" no longer recognized as a valid duration unit for file rotation and retention arguments.
• Ensure stack from the caller is displayed while formatting exception of a function decorated with @logger.catch when backtrace=False.
• Modify datetime used to automatically rename conflicting file when rotating (it happens if file already exists because "{time}" not presents in filename) so it's based on the file creation time rather than the current time.