rillian Move gcc later in the build order.
Building openssl and curl first lets us use TLS for all later
downloads. The curl/openssl included with our Centos:5 base
has compatibility problems with many modern websites.

This slows the cycle time since we update openssl and curl
more often than gcc, which was previously first since it's
one of the slowest packages to build.
Latest commit 941295c Feb 1, 2017