[enh] WolframAlpha no API engine (and tests for both)

 - searx/settings.yml is the right name in second sed line
 - COPY requirements.txt . does not work: "Not a directory"

Conflicts:
	searx/tests/test_engines.py

Better Docker embedded support

[fix]#485 AttributeError: 'module' object has no attribute 'old_where'

[fix] Display multiple answers in wolframalpha_api

[fix]soundcloud.com guest client_id fetches dynamically

The answer is scraped from a js function, so parsing the html tree
doesn't achieve anything here.