Add implementation for a DockerLatentBuildSlave
Add an entrypoint for the DockerLatentBuildSlave
Build the image if not found and the dockerfile is given
Add tests for the DockerLatentBuildSlave
Add documentation for the latent BuildSlave
Small fixes
defer the stop_instance to a thread, don't wait if fast.
Fix the comment about container isolation in the doc. (Thanks @sa2ajj)
Prefix the thread methods with 'thd_'
Don't make the test dependant on private methods
Merge pull request #1344 from benallard/docker_latent

Add a Docker Latent BuildSlave implementation

Fixes ticket:2956
Update styleguide about thd_ prefix for secondary-thread functions.
Address review comments.
fix some highlighing issues

* docker
  * use 'none' for the time being (until Pygments 2.0+) is installed on our builders
  * explicitly say "bash" for a bash snippet
* explicitly say "python" for Cppcheck example
Merge pull request #1350 from benallard/patch-1

Update styleguide about thd_ prefix for secondary-thread functions.
Merge pull request #1351 from sa2ajj/fix-highlighting-issues

fix some highlighing issues for the documentation