demonstrate asynchronous execution (-j (jobs) limits not supported)
limit number of jobs using semaphores
commit examples of workflow and its output in png
integrate asynchronous execution in core.clj
refactoring
remove binary files
add -j as non-flag-short
set-jobs-semaphore got mistakenly lost in merge
error handling
Disable stdin redirection when async is on (jobs > 1) #53
Better error messages #53
Merge branch 'guillaume-async' into feature/empty-dir-async

Conflicts:
	src/drake/core.clj