R to-do

[robertgrant]

• blocking in body tag (see Stata version)
• id option for all functions except start
• multitab % out of all observations
• unitab and multitab option to align numbers (centre as default)
• write crosstab
• write table of descriptive stats, given the data
• return unitab and multitab tables as data frames

[robertgrant]

cumulative % option in unitab