add UDPATE option and manage the update of a file in a dataset
Merge branch 'develop' of https://github.com/mobyle2/mobyle2.lib into develop
correct myaml to export/import correctly between Mongo and YAML.
add unit tests for myaml

(also solves the issue in task #64)
add pyyaml dependency to requirements

as requested in task #65
remove useless 'MOBYLEHOME' code from EDAM import script.
add unit test to illustrate find/fetch problem with mongokit's
embedded docs.
project dir is now computed using pid path and object id instead of
expecting a stored property

TODO: should we keep this rule as is?
return None as project.dir if cannot parse pid_file_path from config.
remove obsolete unit tests setting the project dir
correct unit tests on routing_model.
add unit tests on job to load correctly values from DB.
minor correction in job unit tests

FIXME: end_time reloading now *fails*.
correct unit tests for time in job save/reload
remove the nonworking dot-notation from Job class.
send back the default value of a parameter as ValueData.
fix unit test for default value which is now a ValueData
add 'service' property accessor to the Job class.
change attribute name for Parameter from ctrl to ctrls.

because it is a *list* of controls.
only return the AbstractData part of the ProjectData in get_input_value.

So that the method always returns an AbstractData.