This function takes a package name an generates a two-column table
with the names of each function in the package and the short description
from the help documentation.
Usage
functiontable(pkg, ...)
Arguments
pkg
a string specifying the name of a package,
...
additional arguments to xtable
Value
the output of xtable (as html, or specify type="latex")
Details
useful for Sweave/knit manuals specifying a table of functions
Note that xtable format can also be set with
options(xtable.type="latex") or
options(xtable.type="html").
This function modified from DWin's solution on StackOverflow.com,
http://stackoverflow.com/questions/7326808/