--request-target: instead of --strip-path-slash

[bagder]

... and CURLOPT_REQUEST_TARGET instead of CURLOPT_STRIP_PATH_SLASH.

This option instead provides the full "alternative" target to use in the
request, instead of extracting the path from the URL.

Test 1298 and 1299 updated accordingly.

Idea-by: Evert Pot
Suggestion: https://daniel.haxx.se/blog/2017/06/19/options-with-curl/comment-page-1/#comment-18373

[coveralls]

Coverage increased (+0.07%) to 73.881% when pulling 18c239d on bagder/request-target into b778ae4 on master.

[jay]

what's the use case for this that can't be done with strip leading slash

[bagder]

I'd say they cover pretty much the same use cases. This approach has the benefit in my mind that it makes it more visible and straight-forward to the user as to what is actually sent, while the "strip slash" option is a more subtle description of how to change the transition from a URL to a HTTP request target.

[coveralls]

Coverage decreased (-0.02%) to 73.793% when pulling 629b6c8 on bagder/request-target into b778ae4 on master.