qemu-monitor: migrate to Python!

Just came across the telnet in the stdlib, and got rid of the ugly expect
dependency, nice.

Also implement stdin input now that we have a sane language.

download-dependencies

@@ -88,9 +88,9 @@ automake \
 bc \
 bison \
 build-essential \
+ccache \
 coreutils \
 cpio \
-expect \
 flex \
 gcc-aarch64-linux-gnu \
 gcc-arm-linux-gnueabihf \
@@ -114,7 +114,6 @@ pexpect==4.6.0 \
 "
   if "$gem5"; then
     pkgs="${pkgs}\
-ccache \
 diod \
 libgoogle-perftools-dev \
 protobuf-compiler \