Add patch clamp import and viewer?

[MichaelClerx]

1. Move here from Myokit

• axon
• heka
• wcp
• nanion (not in Myokit now)
• "Sweepsource" class

2. Would require little interface layer in Myokit to use datkit and get (1) DataLog and (2) Protocols (would require own protocol class here)
3. Move the LogViewer from Myokit, including all the ideas to update it. But could then replace Myokit's explorer with a use of datkit's viewer

Considerable change of scope & direction