- sorting of includes
- bracket location
- all arguments on the same hight
- use of auto in the performance/io/disk_io.cpp

Do some small textual changes

fix importing of file export parameters from json

Rename exporter_interface
Move exportor to io directory

Merge branch 'master' of https://github.com/eth-cscs/cell_algorithms into feature/exporter_spike_file

Improve miniapp command line argument handling

* Resolves some conflicts.

Add 'nop_function' helper for trivial functions.

* Reformat some line breaks.
* Remove blank lines after comments.
* Reword/improve some comments.
* Explain what CustomCmdLine does in more detail.
* Remove vestigial declaration of 'args' in
  `CustomCmdLine::reorder_arguments()`

Increased the output size

Save values in a array, to prevent changes on the heap

Remove the flush

* Address issue #74: missing json configuration options.
* Allow parameters from input file to be overriden on command line.
* Missing parameters in json input will defer to defaults.
* Add option for saving current options to json file (allowing
  for json parameter file format discovery.)
* Fix annoying command line argument reordering from TCLAP.
* Fix bug in assignment of `nothing` to a util::optional<T>
  variable.

Moved spike buffer to the manager. This allows reuse the by other registered exporters

Default is false
No output via command line parameters

Make the spikes have realistic id's and timings, the amount of chars to output is now more in line with
realworld output

Added a simple switch to select functionality
No correct file output name setting yet.

file per rank and file per simulation

Add unique _ptr to the model class (will be refactored later to have a manager)

Commit upstream changes