duplicated variable names in summarise overwrites #142
new class NamedListAccumulator to help mutate and summarise
making sure summarise refuses to modify grouping variable. #143
Merge branch 'master' of https://github.com/hadley/dplyr
using NamedListAccumulator for mutate too
 'n =' made test fail
Better value for db_has_table for mysql.
Closes #91
Remove old test code
Clarify goals in readme. Other wording tweaks
Remove package startup message
Dont test compute example because so slow
Revert last change - just makes another ex slow
Merge branch 'master' into cpp-default
More flexible control over printing
Document count_distinct
Polishing intro
Provide wrappers for more basic functions.
Special warning message if you use na.rm in an prefix function
Polishing databases vignette
making sure mutate does not loose variables (was not using NamedListAccumulator) correctly
added missing select.grouped_cpp so that it preserves the grouping. closes #147