Tweak examples and fix buglet
Start writing some tests
Add reasonable do() behavour for ungrouped data frames
Fix typo in tbl_dt
In tbl_dt, set explicit class
Move do methods into one file
Remove spurious whitespace
Add basic do() implementation for data table
Remove duplicated entry
Turn threshold for progress bar down to 2s
Move do.tbl_sql into do.r
Update do interface for databases
News and docs improvements
Document missing args
Don't document lapply_cluster
R CMD check fixes