More sensible (re)loading of the configuration files, encapsulation of
certain operations and other fixes

* mix.R(get_.*): Generate various filenames.

* mix.R(various intermediate wrappers around RMassBank calls):
  removed.

* run.R(presc.do): Adjust to changes in mix.R

* man: Update docs.

* NAMESPACE: Update exports.

* README.org: New file.

The main issue is that I have removed type='FORK' everywhere it
clearly produced issues. I should probably do that in presc, too.

* README.org: New file.

Finally plotting works nicely.

* R/mix.R(presc.plot): New argument.
  [pal] Colorbrewer palette.

* R/mix.R(presc.plot): New function. Plots the prescreening data.

R/mix.R(RMB_EIC_prescreen_df): Fix. Data frame now collects all
children.

* R/mix.R(presc.p): New function. Paralellises presc.single.

* NAMESPACE: New export.

* man: Update docs.

* R/mix.R(presc.v): New function. Vectorises presc.single.

* NAMESPACE: Update exports.

* man(presc.single.Rd,presc.v.Rd): Update docs.

* R/mix.R(RMB_EIC_prescreen_df): New function. Instead of pdf file
  with plots, this one records the data.frames to laters serve as
  inputs to plotting stages.

* R/mix.R(presc.single): Now loads the component list properly.

This reverts commit a36f514a.

The said commit was unnecessary.

* R/mix.R(gen_file_table

* R/mix.R(gen_cmpdl_and_load): Fix typo.

* R/mix.R(gen_stgs_and_load):
  Fix argument.

* R/mix.R(presc.single): Export

* NAMESPACE: Add exports

* R/mix.R(presc.single): Update.

* R/mix.R(gen_stgs_and_load,gen_cmpdl_and_load,gen_file_table): New
  functions.

* R/mix.R(presc.single): New function.

* man/presc.single.Rd: New documentation.

* README.org: New file.

* R/mix.r(p.sw,v): idir

* R/mix.R(p.sw,v): Update.

* mix.R(p.sw,v): Update. Attach a suitable name (that has an extension
  that can be stripped) to the combined object.