Settings file has to use UTF-16 LE encoding

[DStrelak]

Version: 1.0.9

Problem:
When you try to load settings file via REST API, the settings file has to be encoded using UTF-16 LE.
However this is not documented neither here: http://www.warpem.com/warp/?page_id=416 nor here: https://github.com/cramerlab/warp/blob/master/Warp/WebAPI.cs
Loading settings file in different encoding results in no error (200 - success), but changes are not applied.
This is excruciating to debug.

Expectations:
Requirements on the encoding is properly documented
RESP API returns error when loading fails, with a message indicating wrong file encoding