Bhv 12513 Calendar: First day of week does not changed based on locale 

Issue
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Even though user change locale, the day label sequence is not changed.

Cause
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ilib.DateFmt is not updated when locale is changed

Fix
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Modify calendar logic to update Date formatter based on locale changing.
Clear formatter's name to keep consistency.

Enyo-DCO-1.1-Signed-off-by: David Um david.um@lge.com