update NEWS
register hxskel format with full type rather than extension
implement identification/dispatch for Amira hxlineset neurons
verbatim copy of ReadNeuronFromAM
change default NeuronName to filestem w/o extension
full implementation of read.neuron.hxlineset

* and a test
pass ... to as.neuron.ngraph from read.neuron.hxlineset
add tests for identifying hxlineset files

* presently fail for gzipped files
fix a bug in testing for missing origins revealed when first point is floating
specify magician when registering amira types so that magic actually used
Give amiratype a bytes argument to give it a faster precheck for amiramesh
teach is.amiramesh to handle gzipped files
getformatfuns now decompresses magic from gzipped data
simplify is.hxskel and is.hxlineset

is.amiratype already includes a check for amiramesh
add failing test for mis-parsed ContentType
move checkLabel out of .ParseAmirameshParameters since called recursively

* seems like a bad idea to keep on redefining checkLabel
remove any commas from lines with quoted entries

* and use scan(text=) to avoid explicit handling of textConnection
ensure that amiratype does not return an attributed string

* which was the case e.g. for SkeletonGraph content
Merge branch 'fix/parseamiracontenttype' into feature/hxlineset

* fix/parseamiracontenttype:
  ensure that amiratype does not return an attributed string
  remove any commas from lines with quoted entries
  move checkLabel out of .ParseAmirameshParameters since called recursively
  add failing test for mis-parsed ContentType
correctly set up test for identify gzipped hxlineset by bytes