--git can update existing bosh source

Also explicitly building/install gems to avoid
an unsolvable bug in bosh's "rake install" where
bosh_deployer was not being installed correctly.
Remove commented ideas
Replacing rvm with rbenv for inception VM ruby
switching to a debian pkg for ruby

need a ruby installed that works in root & vcap user
Don't need to pass GEM_PATH/GEM_HOME in remote sudo

These stopped "gem install xyz" working; and were
required for using rvm.
after deploy, cleanup ~vcap file permissions
ssh command uses vcap user instead of original username
Merge pull request #12 from danhigham/0c1d003bb963a7828ebb33a5757e8928804f0970

Install qemu-kvm to provide qemu-img binary
inception vcap has TMPDIR to /var/vcap/store/tmp
Merge pull request #13 from danhigham/master

Make regex for striping types from YAML more generic
/var/vcap/store is assigned to vcap user
Fixed ports in security group for AWS
fix the yaml cleanup gsub to remove prefix space
include port 4222 for nats
use the attached disk for $TMPDIR for stemcell creation
Cleanout previous stemcell work area before repeating
symlink stemcell tmpdir into mounted volume [fixes #21]
more descriptive deploy flags [fixes #19]
install tmux on inception vm [fixes #25]
new vcap user gets $EDITOR=vim by default [fixes #30]