Minor refactoring in the ONOS cell configuration:
 * Each cell-specific variable is explicitly listed
   in the cell config file:

 * Cleanup and bug fixes inside bash_profile:
   - Don't export explicitly OCI and ONOS_CELL, because those
     are now exported in the cell config file
   - unset ONOS_CELL, ONOS_NIC, ONOS_FEATURES (the last two weren't
     unset before)
   - The built-in "cell" function shows OC1 to OC9 instead of OC0-OC9;
     OC0 is never used/setup anywhere else

 * Added two new shell commands:
   - tools/test/bin/onos-lsit-cells : lists existing ONOS cell configurations
     It is the equivalent of the "cells" built-in bash command
   - tools/test/bin/onos-show-cell : shows the configuration of an ONOS cell
     It is the equivalent of the "cell" built-in bash command, but
     it can show also the configuration of any ONOS cell (not only
     the default one).
diff --git a/tools/test/cells/office b/tools/test/cells/office
index 5ec108f..72520a0 100644
--- a/tools/test/cells/office
+++ b/tools/test/cells/office
@@ -1,6 +1,9 @@
 # ProxMox-based cell of ONOS instance; no mininet-box
-export ONOS_FEATURES="webconsole,onos-api,onos-core-trivial,onos-cli,onos-openflow,onos-app-fwd,onos-app-mobility,onos-app-tvue,onos-app-proxyarp"
+export ONOS_CELL="office"
 export ONOS_NIC="10.128.4.*"
 export OC1=""
+export OCI="${OC1}"
+export ONOS_FEATURES="webconsole,onos-api,onos-core-trivial,onos-cli,onos-openflow,onos-app-fwd,onos-app-mobility,onos-app-tvue,onos-app-proxyarp"