Changes from 1.19.99.2 to 1.19.99.3

- fix memory leaks

- fix regression: implement cancelling with libcurl

use cc cc-lib cc-shared pkg-config

set maj_ver 1

set min_ver 99

define PKG_API [expr $maj_ver * 1000000 + $med_ver * 1000 + $min_ver]

define VERSION $maj_ver.$med_ver.$min_ver[expr {$dev_ver ? ".$dev_ver" : ""}]