added R 3.0.1 compat info
fixes #57
do not alter key sort order (important with combine) could address #58
for numeric vectors
handle also matrix and data frame
faster solution for df and matrices, fixes #58
update for release 2.2.2
gotta avoig duplicates under any circumstances
release candidate
fix the case of empty string key
no need to special case win here
new release candidate
clean up old builds
win build
added win compatibility
merge from 2.2.2 and keep aiming for 2.3.0

Merge branch 'master' into dev

Conflicts:
	docs/new-in-this-release.Rmd
	pkg/DESCRIPTION