curl*3: added small examples

and some minor edits

docs/libcurl/curl_easy_setopt.3

@@ -499,6 +499,16 @@ the library is too old to support it or the option was removed in a recent
 version, this function will return \fICURLE_UNKNOWN_OPTION\fP. If support for
 the option was disabled at compile-time, it will return
 \fICURLE_NOT_BUILT_IN\fP.
+.SH EXAMPLE
+.nf
+CURL *curl = curl_easy_init();
+if(curl) {
+  CURLcode res;
+  curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
+  res = curl_easy_perform(curl);
+  curl_easy_cleanup(curl);
+}}
+.fi
 .SH "SEE ALSO"
 .BR curl_easy_init "(3), " curl_easy_cleanup "(3), " curl_easy_reset "(3), "
 .BR curl_multi_setopt "(3), "