PP plugin: retrieve multiple files.

[yakutovicha]

Before #428 was merged it was possible to define an additional_retrieve_list setting to retrieve more files. This is needed, for example, if one wants to download multipe output files which are produced by plot orbitals run:

&INPUTPP
  filplot = 'aiida.filplot'
  kband(1) = 12
  kband(2) = 12
  kpoint(1) = 1
  kpoint(2) = 24
  outdir = './out/'
  plot_num = 7
  prefix = 'aiida'
/
&PLOT
  fileout = 'aiida.fileout'
  iflag = 3
  output_format = 6
/

In that case, pp.x will produce a number of files named as follows: aiida.filplot_K***_B***aiida.fileout.

The possible solution for this is to either return additional_retrieve_list setting back or to define a wildcard instead of

aiida-quantumespresso/aiida_quantumespresso/calculations/pp.py

Lines 217 to 220 in 5e06a62

	if self.inputs.metadata.options.keep_plot_file:
	calcinfo.retrieve_list.append(self._FILEOUT)
	else:
	calcinfo.retrieve_temporary_list.append(self._FILEOUT)