Fix dead-lock issues, improve Camera:AcqThread::start/stop API:

* Signature forces the caller to lock the mutex of the condition to wait on
4 jobs for 20-decouple-from-ctcontrol in 6 minutes and 10 seconds
Status Job ID Name Coverage
  Build
failed #142054
linux
build-linux

00:06:10

failed #139338
linux
build-linux

00:02:31

 
  Build Noarch
skipped #139339
conda
build-noarch
 
  Deploy
skipped #139340
linux conda allowed to fail manual
deploy-devel
 
Name Stage Failure
failed
build-linux Build
    raise subprocess.CalledProcessError(proc.returncode, _args)
subprocess.CalledProcessError: Command '['/bin/bash', '-o', 'errexit', '/opt/conda/conda-bld/lima-camera-slsdetector_1600844873985/work/conda_build.sh']' returned non-zero exit status 2.
Running after_script
bash: cannot set terminal process group (-1): Inappropriate ioctl for device
bash: no job control in this shell
groupadd: group 'conda' already exists
useradd: user 'conda' already exists
Uploading artifacts for failed job
ERROR: Job failed: exit code 1