[mod] add Makfile targets for search.checker.<engine_name>

To check all engines:

    make search.checker

To check a engine 'google news' replace space by underline:

    make search.checker.google_news

To see HTTP requests and more use SEARX_DEBUG:

    make SEARX_DEBUG=1 search.checker.google_news

To filter out HTTP redirects:

    make SEARX_DEBUG=1 search.checker.google_news | grep -A1 "HTTP/1.1\" 3[0-9][0-9]"
    ...
    Engine google news                   Checking
    https://news.google.com:443 "GET /search?q=life&hl=en&lr=lang_en&ie=utf8&oe=utf8&ceid=US%3Aen&gl=US HTTP/1.1" 302 0
    https://news.google.com:443 "GET /search?q=life&hl=en-US&lr=lang_en&ie=utf8&oe=utf8&ceid=US:en&gl=US HTTP/1.1" 200 None
    --
    https://news.google.com:443 "GET /search?q=computer&hl=en&lr=lang_en&ie=utf8&oe=utf8&ceid=US%3Aen&gl=US HTTP/1.1" 302 0
    https://news.google.com:443

 "GET /search?q=computer&hl=en-US&lr=lang_en&ie=utf8&oe=utf8&ceid=US:en&gl=US HTTP/1.1" 200 None
    --

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>