define neuronformats registry and use it in new read.neuron
roxygenise to add docs & update namespace
neuronformats docs
remove duplicate parameter docs
partial implementation of read.neuron.swc

* still waiting on implementation of ngraph stuff
Ensure ... is passed from as.neuron.dataframe to neuron() 

* via as.neuron.ngraph
* this allows e.g. the filename to be set
Implement read.neuron.swc
remove duplicate importFrom igraph

* right now I am importing the whole namespace
* this gives a duplicate warning for specific imports
* either all imports must be specified with @importFrom, or none
fix roxygen tag errors
make sure that we can pass additional arguments through read.neuron
move example of setting NeuronName to read.neuron

* this should be the default point of entry anyway
  maybe even consider _not_ exporting read.neuron.swc
add a test for setting NeuronName
bring over read.neurons from AnalysisSuite
basic test for read.neurons
Make read.neuron.swc package private
remove unimplemented read.neuron.neurolucida
Merge branch 'feature/ioregistry'

* feature/ioregistry:
  remove unimplemented read.neuron.neurolucida
  Make read.neuron.swc package private
  basic test for read.neurons
  bring over read.neurons from AnalysisSuite
  add a test for setting NeuronName
  move example of setting NeuronName to read.neuron
  make sure that we can pass additional arguments through read.neuron
  fix roxygen tag errors
  remove duplicate importFrom igraph
  Implement read.neuron.swc
  Ensure ... is passed from as.neuron.dataframe to neuron()
  partial implementation of read.neuron.swc
  remove duplicate parameter docs
  neuronformats docs
  roxygenise to add docs & update namespace
  define neuronformats registry and use it in new read.neuron
Bump package version to 0.7