add digbt engine - fixes #638

Add Hoogle search engine

eg. pageno=1,21,41,... instead of 20,40,60,...

Unfortunately, it is quite slow so it is disabled.
Furthermore, the display of number of files is wrong
on digbt.org, so it is not displayed on searx.

Add Microsoft Academic search engine

Add missing blank lines after class or function definition.

[enh] infinite scroll

resolves #649

openrepos: Meego/Sailfish application repository

[fix] delete trailing quote

Add Crossref search engine and DOAI rewrite plugin

set type of cursor to pointer in advanced search

[enh] More data from Wikidata

new toggle button - closes #284, #625

TODO:
    merge attributes

disambiguation and tags are in local language

TOFIX:
    needs to query the api every time to know each label's name

[mod] remove the kickass engine from settings.yml

support time range search