ensure tgtd is running in debug mode

this change enables on-the-fly tgtd debug before starting cinder

Change-Id: I193bfd77c5a82e8347d75e2a7fe670a6e25f5558
xenapi: increase default memory to 3G

Devstack was swapping with 2G

Change-Id: I8fe77591cb0ca0f946028d7219b43d77eea3419f
Merge "ensure tgtd is running in debug mode"
Merge "xenapi: increase default memory to 3G"