Document the real meaning of the data bits enumeration values

Change-Id: I7e12e26e6676ecb064eb06599234d2844041335d
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>
Reviewed-by: Sergey Belyashov <Sergey.Belyashov@gmail.com>
Fix a typo in the 5.2.0 changelog text

Change-Id: I211a417d1e4af8e22a2fd736093f099b8fd15cd8
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>
Reviewed-by: Sergey Belyashov <Sergey.Belyashov@gmail.com>
Mark the 1.5 stop bits in the documentation as Windows only

Change-Id: I58ee8bf1913c773f345b23bd01d1cc3fefc5f6ac
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>
Reviewed-by: Sergey Belyashov <Sergey.Belyashov@gmail.com>