allow subset.spiketimes with duplicated channels but warn

* will only keep first matching sweep
* add test for this
Prepare 0.7-2
Merge branch 'release/0.7-2' into develop

* release/0.7-2:
  Prepare 0.7-2
typo in NEWS
whitespace tabs -> 2 spaces
Add new mergedwaveinfo attribute in merge.spiketimes

* this can be used to figure out which wave contains
  which sweep
Docs for merge.spiketimes mergedwaveinfo attribute
Rename as.spiketimes to spiketimes to indicate that it is default constructor

* also move documentation for spiketimes class to this function
roxygenise

* also remove redundant man page
Include all examples within package

* i.e. no more JData dependencies
STY Change quoting of + and [.spiketimes function definitions

* mostly because the TextMate syntax highlighter can understand this ...
better docs plot.spiketimes

* also shorten some example lines to avoid CRAN ire
Prepare 0.7-3
Merge branch 'release/0.7-3' into develop

* release/0.7-3:
  Prepare 0.7-3