add tools::http for generic HTTP GET and move HttpsConnector there

...to avoid having the tools:: module depend on api2.

The get_string function is based directly on hyper and thus relatively
simple, not supporting redirects for example.

Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>

src/tools.rs

@@ -37,6 +37,7 @@ pub mod loopdev;
 pub mod fuse_loop;
 pub mod socket;
 pub mod zip;
+pub mod http;
 
 mod parallel_handler;
 pub use parallel_handler::*;