ENH: Compile git with SSL support

Older versions of git included in older linux distributions are not able
to download source from Github. A newer version is required with a newer
OpenSSL. This requires to also build curl with the same OpenSSL.

CMake is downloaded precompiled if available (64bits system) or compiled
from source otherwise.

imagefiles/build-and-install-openssh.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+set -ex
+
+OPENSSH_ROOT=V_7_6_P1
+
+cd /usr/src
+curl -LO https://github.com/openssh/openssh-portable/archive/${OPENSSH_ROOT}.tar.gz
+tar -xvf ${OPENSSH_ROOT}.tar.gz
+rm -f ${OPENSSH_ROOT}.tar.gz
+
+OPENSSH_SRC_DIR=openssh-portable-${OPENSSH_ROOT}
+cd ${OPENSSH_SRC_DIR}
+
+autoreconf
+
+./configure --prefix=/usr/local
+
+make -j1 install
+
+cd /usr/src
+rm -rf ${OPENSSH_SRC_DIR}