roles/burp-server: Deploy BURP server

The *burp-server* role installs and configures a BURP server. It is
adapted from a previous iteration, and should support CentOS/RHEL/Fedora
and Gentoo, as well as both BURP 1.x and 2.x (depending on which version
gets installed by the system package manager).

To manage the certificate authority, the *burp-server* role uses the
`burp_ca` command. This has the advantage of not requiring any external
certificate management, but effectively binds the CA to a specific
machine.

roles/burp-server/templates/CA.cnf.j2

@@ -0,0 +1,33 @@
+# simple config for burp_ca
+
+RANDFILE                = /dev/urandom
+CA_DIR                  = {{ burp_ca_dir }}
+
+
+[ ca ]
+dir                     = $ENV::CA_DIR
+database                = $dir/index.txt
+serial                  = $dir/serial.txt
+certs                   = $dir/certs
+new_certs_dir           = $dir/newcerts
+crlnumber               = $dir/crlnumber.txt
+
+unique_subject          = no
+
+default_md              = sha256
+default_days            = 7300
+default_crl_days        = 7300
+
+#????
+name_opt                = ca_default
+cert_opt                = ca_default
+
+x509_extensions         = usr_cert
+copy_extensions         = copy
+policy                  = policy_anything
+
+[ usr_cert ]
+basicConstraints        = CA:FALSE
+
+[ policy_anything ]
+commonName              = supplied