[Rd] Print multivariate time series (PR#7255)

[javimunozlara at wanadoo.es]

Full_Name: Javier Muñoz
Version: 1.9.1
OS: Windows NT 4.0
Submission from: (NULL) (193.128.25.20)


The print.ts function don't show properly the information about year for class
mts objects.
An example:

x <- ts(1:24, end = c(2004, 8), frequency = 12)
print(cbind(x, x))

#it shows Jan 2002 instead of Jan 2003