Optional arguments should not be done with Varargs

[egli]

According to Stuart Sierra optional arguments shouldn't be done with varargs. His arguments make sense. There are a few places in the code where this is used and could be improved. The following is a redacted grep output with irrelevant occurrences deleted:

-*- mode: grep; default-directory: "~/src/mdr2/" -*-
Grep started at Wed Jun  3 12:07:06

find . -type d \( -path \*/SCCS -o -path \*/RCS -o -path \*/CVS -o -path \*/MCVS -o -path \*/.svn -o -path \*/.git -o -path \*/.hg -o -path \*/.bzr -o -path \*/_MTN -o -path \*/_darcs -o -path \*/\{arch\} \) -prune -o \! -type d \( -name .\#\* -o -name \*.o -o -name \*\~ -o -name \*.bin -o -name \*.lbin -o -name \*.so -o -name \*.a -o -name \*.ln -o -name \*.blg -o -name \*.bbl -o -name \*.elc -o -name \*.lof -o -name \*.glo -o -name \*.idx -o -name \*.lot -o -name \*.fmt -o -name \*.tfm -o -name \*.class -o -name \*.fas -o -name \*.lib -o -name \*.mem -o -name \*.x86f -o -name \*.sparcf -o -name \*.dfsl -o -name \*.pfsl -o -name \*.d64fsl -o -name \*.p64fsl -o -name \*.lx64fsl -o -name \*.lx32fsl -o -name \*.dx64fsl -o -name \*.dx32fsl -o -name \*.fx64fsl -o -name \*.fx32fsl -o -name \*.sx64fsl -o -name \*.sx32fsl -o -name \*.wx64fsl -o -name \*.wx32fsl -o -name \*.fasl -o -name \*.ufsl -o -name \*.fsl -o -name \*.dxl -o -name \*.lo -o -name \*.la -o -name \*.gmo -o -name \*.mo -o -name \*.toc -o -name \*.aux -o -name \*.cp -o -name \*.fn -o -name \*.ky -o -name \*.pg -o -name \*.tp -o -name \*.vr -o -name \*.cps -o -name \*.fns -o -name \*.kys -o -name \*.pgs -o -name \*.tps -o -name \*.vrs -o -name \*.pyc -o -name \*.pyo \) -prune -o  -type f \( -name \*.clj \) -exec grep -i -nH -e \& {} +
./src/mdr2/encode.clj:68:    :as production} & [volume]]
./src/mdr2/pipeline2/scripts.clj:10:(defn validate [input & {:keys [mathml-version check-images] :as opts}]
./src/mdr2/pipeline2/scripts.clj:13:(defn daisy3-to-epub3 [input & {:keys [mediaoverlays assert-valid] :as opts}]
./src/mdr2/pipeline2/scripts.clj:16:(defn epub3-to-daisy202 [input & {:keys [temp-dir output-dir] :as opts}]
./src/mdr2/pipeline1.clj:60:  [input output & {:keys [bitrate stereo freq] :as opts}]
./src/mdr2/views.clj:111:(defn file-upload-form [request id & [errors]]
./src/mdr2/views.clj:145:(defn catalog [request & error]
./src/mdr2/views.clj:234:(defn production-bulk-import-form [request & [errors]]
./src/mdr2/views.clj:305:  [request & [errors]]
./src/mdr2/views.clj:411:(defn production-split-form [request id & [errors]]

Grep finished (matches found) at Wed Jun  3 12:07:07