Bug Fix: long dummy column name is trucated by the database

which brings lots of errors. Solution is to use a short unique.string.
Added verbose option in glm
Bug fix: All categorical variable has special characters in level values
Bug fix: Using names to change column names uses double quotes
Bug fix: handle boolean correctly in generic.bagging
Changed address in PivotalR paper
Added plr functions
Let the result of map carry the grouped data information
Updates
Fixed lots of small bugs
Exported declare
Fixed a potential bug
Allow arguments use same type as return
Added aggregate
Fixed bugs