Going through multiple reverse proxy will store multiple scheme and port in HTTP header separated by a comma. Shaarli will use the first one to generate server_url.
Additions:
- [makefile] check versioned files are not executable
- [travis] call the new make target
Signed-off-by: VirtualTam <virtualtam@flibidi.net>
* `get_http_url()` renamed to `get_http_response()`.
* Use the same HTTP context to retrieve response headers and content.
* Follow HTTP 301 and 302 redirections to retrieve the title (default max 3 redirections).
* Add `LinkUtils` to extract titles and charset.
* Try to retrieve charset from HTTP headers first (new), then HTML content.
* Use mb_string to re-encode title if necessary.
