Update NEWS
Trim trailing whitespace
Correct path for Rtools when no registry entry. Fixes #201
Rcpp attributes and improvements to load_all build environment
Merge branch 'rcpp-attributes-build'

Conflicts:
	NEWS
Fix deprecated httr call. Fixes #170
check_cran(): use new tempdir for each run. Fixes #182
check_cran: don't remove existing libpath. Fixes #199
Cleaner method for storing original libpath
check_r_cmd: don't require pkg argument
check_r_cmd: add argument for destination directory
check_cran: use check_r_cmd instead of own call to R()
Merge pull request #205 from wch/use-check-function

check_cran(): use check_r_cmd() instead of R()
check: make CRAN version check optional. Fixes #172

This commit also switches from using --as-cran, to setting environment
variables, as described in R Internals.
Update NEWS
Move CRAN env vars out to separate function
Merge pull request #206 from wch/no-check-ver

Make CRAN version check optional
check: better help for cran option
check: add force_suggests option
check_cran: don't force suggested packages