minor problems (if problems at all): <ESC> in RGui; finding some (PR#799)

[These things don't seem to be of too great importance and may well not meet
the criteria of a "bug", but, for what it's worth,I thought I'd submit them
to r-bugs anyway:]

This is the R version:

version

         _              
platform i386-pc-mingw32
arch     x86            
os       Win32          
system   x86, Win32     
status                  
major    1              
minor    2.0            
year     2000           
month    12             
day      15             
language R 

This is what we noticed:

1) In RGui, when something is typed in a command line, pressing <ESC> in
R1.0.0 used to delete the written text and go to a blank new line; in R1.2.0
the text is not deleted and the user is prompted for new input in the same
line.
Of course, this is rather a "cosmetical" issue, but it might be worth
considering to change this behaviour back to what it used to be in R1.0.0?

2) It looks like if for some functions, their help pages cannot be accessed
directly via "?" or "help". For example, ?install.packages, or ?setwd, won't
find the appropriate help page (I am using winhelp, to be specific).
This might be because e.g. "setwd" shares the same help file with "getwd",
and it looks like only "getwd" is part of the index of the help system.
Here, the same holds for R1.0.0.