setdiff.neuronlist second arg can be character vector
Give find.neuron an invert arg

* closes #172
Give find.soma an invert arg as well

* and simplify docs in process
Fix handling of StartPoint in find.soma

* closes #173
Simplify handling of colours when plotting points only
Fix node colours when WithAllPoints=TRUE

* closes #175
Plot end points in blue not green

* since default node colour for simple points is green when all nodes plotted
Document that WithText plots indices not PointNo
Add swc format conversion of 2 neuroml v1 files

* from Neuronland converter
* will use for testing
fix col names of cabled

* when only one non-standard column
Fix - actually fetch fract_along_parent
as.data.frame.morphml_cell handles proximal nodes

* previously ignored proximal nodes
* should probably renumber PointNos
failing tests comparing swc vs neuroml
renumber points after neuroml import

* since they do not really match anything specific in input file anyway
warn if cable does not connect to end of parent seg
suppress warnings in neuroml tests

* relating to handling of fract_along_parent
Document and export read.neuron.neuroml
clarify message when fract_along_parent!=1
Correct handling of SWC label for NeuroML import
Document and export read.morphml