Split exported waveform and data
Change data export tags and variable names
Rename EXPORT_SIGDELIM to EXPORT_LINEDELIM
Export and import settings
Merge branch 'export_import_settings'
Release v0.12.0: Split exported waveform and data/settings

Separate HTML textarea into waveform and data/settings textareas
Export and import settings as well as signal data
Backwards-incompatibility: data export tag reads DATA instead of DATA_EXPORT