Fixed issues identified by Harm Buisman

* Removed leading zero in package number. i.e., 4.7 instead of 4.07.
* better handling of nearly constant time series, and nearly linear time
series
* improved handling of missing values in rwf()
* corrected fitted values and residuals in meanf() for time series data
* bats() and tbats() now handle missing values in the same way as ets().
i.e., using longest contiguous portion.

Also changed ::: to :: throughout.