[Rd] format.POSIXlt drops characters following percent sign (PR#8975)

[jhallman at frb.gov]

Full_Name: Jeff Hallman
Version: 2.3.1
OS: Windows
Submission from: (NULL) (132.200.32.34)


Internal(format.POSIXlt(as.POSIXlt(Sys.time()), "%Y%m%d%q", F)) 
      Linux R-2.2.1 returns "20060613%q".
    Windows R-2.3.1 returns "20060613" dropping the "%q".  

The documentation says "Any character in the format string other that the '%'
escape sequences is interpreted literally".  Since "%q" is nowhere listed as an
escape sequence, the Windows R-2.3.1 result appears to be incorrect.

The Unix 'date' command gives the same result as Linux R-2.2.1.