SignalEntry with csv file + refactorings

Version 1.5.0

new

• added option to read & write SignalEntry with csv file

changed

• moved channel naming and data type inference to separate methods
• simplified Entry._get_index() and Entry.add_entry(), CustomAttributes.to_element()
  -> caution: stacked entries will still be removed only partially with Entry.remove_entry()
• separate remove_entry method for Unisens class
• fixed writability of attrib when passed at initialization
• setting kwargs always with set_attrib independent of passing to __init__ or set_data
• removed cause for exception in Entry._autosave(): always have a _parent attribute (even when copying)
• removed unreachable code and removed 'return True' where raising exceptions instead of returning False
• refactored paths: no addition of strings, using os.path...
• many minor additions in formatting, typing, comments and docstrings

deprecated

• read_unisens: will be restricted to internal use
• SignalEntry.get_data() argument return_type: argument is unused and will be removed
• Entry subclass CustomAttribute: no use since it doesn't match CustomAttributes.add_entry(); usable alternative is CustomAttributes.set_attrib()
• SignalEntry / ValuesEntry.set_data() will require channel names (deprecating the automatic naming). They can be supplied by passing the argument ch_names or by copying and passing the channel attribute from another entry. In the future, channels will be used to verify data orientation.