listRuns() output wraps and difficult to read

[Peter Slaughter]

The listRuns() command prints output to the R console regardless of the current console
width, so line wrapping ensues, which makes the ouput very difficult to read.

This command should query the console width and print the output so that it fits in
the console without line wrapping. There doesn't appear to be an R or RStudio option
to control line wrapping, so we will have to alter the line width to fit within the current.

[Peter Slaughter]

The listRuns() method now adjusts the output width to the current width of the
console, using getOption("width"), which is set to 80 characters by default, and is
updated by Rstudio when the console window is resized (needs to be set manually if
R is invoked from a terminal window)

Output columns are removed from the right of the output as needed, as the columns have been
ordered from most important to least important from left to right.

If the user wishes to see the full output, regardless of console width and resulting line wrapping, they can include the argument full=TRUE.

The narrowest output is 76 columns, which fits within the default 80 columns:

> listRuns(rc)
Seq   Script                         Tag                  Start Time              
13    Console log: rank-plots.log    rank plots           2017-02-01 16:18:11 PST 
12    Console log: rank-plots.log    rank plots           2017-02-01 16:04:56 PST 

Changes made in commit 487ccb3