Etabackend

**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

1. open multiple windows at the same time
2. zoom everywhere
3. minor fixes of the GUI
4. spearte menu bars
5. default setup for ip,port,and ETA_LIB
6. improved packaging for windows