General TODO's to make R-package suitable for Bioconductor

[snaketron]

This is a general TODO list

• [x] input checks

• [x] #12

• [x] #13

• [x] #14

• [x] #15

• [x] #18

• [x] #19

• [X] DESCRIPTION + NAMESPACE update

• maybe we need to use some interfaces provided by Bioconductor