Etabackend

1. installer makes a pop-up for installation guide
2. assign CHN16 as the first marker for hydraharp devices.
3. automatic detection for qutag formats

**NOTE: ``ETA_LIB-win64.zip`` is updated for the new Python 3.7 environment. If you have the ``site-packages`` from an old ETA version already, please update it.**

1. upgrading to Python 3.7
2. update incremental_cut for better real-time support

1. fixing ETA popup for eta.display()
2. support typing, pathlib
3. make file dialogue staying on top
4. improved usability of lifetime.eta

**NOTE: find_start is renamed to infer_start_from_stop**
1. fix: bug of browse button
2. add start(LAST_SYNC), start(SYNCS)
3. better file format indicator `cut=eta.simple_cut(file,format=FORMAT_SI)FORMAT_SI is used for swabian instruments`
4. add Pathlib into the software stack
5. fix: external labels overlap with circles in Instrument Designer
6. fix: SHIFT+T also adds trigger if focus is on code panel
7. fix: simple_cut crashes the backend for Swebian Instrument timetags.

**NOTE: The recipes should be updated to work with this version:**
**All Acquisition Devices and Parameters(Variables) should be deleted and recreated.**

1. improved New dialog with integraed ETAHub
2. add browse button
3. record() made smart
4. update recipes
5. fix a bug when adding Acqustion Device
6. fix a bug when using a emit() on a non-continous channel number

1. browser for files
2. New button and default recipe
3. hints for create panel
4. giant blobs
5. improved help for instrument designer