HAL plugin should use WP-s HTTP API

Hi,

HAL plugin uses hand-written curl routines, instead of taking advantage of WP’s own HTTP classes. This prevents the plugin from sanely integrating WP’s global configuration. For example, the proxy configuration in WP is ignored, rendering the plugin useless in some environments.

See: https://codex.ww.wp.xz.cn/HTTP_API

Thank you for the plugin and for your attention on this bug.

https://ww.wp.xz.cn/plugins/hal/