Use INSTALL_PATH env variable to set rocksDB installtion path instead of using sed hack

Problem: If one of the donwload task fails the script do not stop and
the other task continue to donwload sources.

Solution: If one of the task fails, print an informative error message
and send a signal to the parent process that kills all the spawned tasks
and exits with error code.

Also, startup and shutdown scripts now have a new argument
to decide on where the created pssh hostfile is stored.

mdtest summary calculation of multiple iterations might be flawed.
Also Daemon is restarted for each iteration.

Review and fixes that died when rebasing all commits

Nafi3 authored Mar 12, 2018 and Marc Vef committed Mar 23, 2018

This commit gives new options regarding separation of metadir and rootdir location. If only rootdir destination is given both metadata and data is stored at the same path

In the case the host running the startup script is not one of the node
that will run adafs it does not make sense to check for the binary of
the daemon locally.

When rocksdb is build with jemalloc linking with adafs was failing

The download script do not work if the specified output path
contains more then 1 non-existing folder.
This is due to the -f flag used in the readlink command.
We now use the less strict -m one.

Source folder was removed if existed before but never recreated

Since the download of sources are performed in parallel, we cannot use
anymore a single log file.

The output of the download commands has been reduced to errrors only and
it will be outputted directly on stderr. Thus the log file stuff have been
completely removed.

Moreover the clonedeps function now takes the REPO as second parameter
and additional (non mandatory) git flags as fourth parameter.

Additional fixes have been introduced to run commands in script mode
(-q, -f, ...)

For dependencies in which a specific tags is specified we can download
the code snapshot instead of cloning the whole repo.

Perform all the download and git clone action in parallel using several
processes.

Due to the new parallel use of the clonedeps and wgetdeps functions,
some adjustment to printed message has been made. Now the function write
on stdout only once when they complete.