cleanup imports
minor pyflakes cleanups
remove line that could never be reached in analogsignal
fix testing issue with hdf5io nested function scope
fix potential bug in alphaomegaio and plexonio with multi-datatype format strings
fix missing and unneccessary variables in neuroshareio
fix bug in error message string in test.tools
fix getattr and setattr in spike2io HeaderReader
fix missing and unneeded variables in plexonio
fix bug where elphyio could return a list then call to_list on it
fix bug in neuroshareio where variable is called before it is declared