Remove unused import

upgrade to 2.0.18

support the centos 7.x

fix the default route issue.

Update version to WALinuxAgent-2.0.18.rc5

Update version to WALinuxAgent-2.0.18.rc4

Fix ClientAliveInterval setting in sshd_config.

yum clean all before search for packages.

Update version to 2.1.4.rc0

tag the rc2.