Channelpack

* Docs made available. Readme updated.
* Update docstring in ChannelPack.load
* Comments in the pulltxt module on possible alternative regex.

* Bugfix (hopefully) with the start and stop conditions. Addition in function
_startstop_bool in datautils module. Start conditions could be "ignored".

* Update append_load method in pack.ChannelPack. Keep data on all files loaded
in metamulti dict, including the new file.

* Add method rebase in ChannelPack, rebase and align a channel.

* Editorials on the README file. Some updates in the setup.py file.

* Initial release