modify sys.path manipulation to work without and WITH MOBYLE_HOME
reoganize code

add new package level engine which group all module of the mobyle2 engine itself
modify import according to this new package
add rules which work like plugin system

user can add rules for job routing in directory  mob2exec/routing_rules/
and the modules job_routing/rules.py allow to register them
the dispatcher will use them
remove extra spaces
remove __all__
relax constraint on rule signature

it could be possible to add some extra parameters in definition of
rule function
the first parameter must be job
add more function rules, for testing framework
transform mob2exec in package
add  execution systems

set up the framework to handle the exexcution systems
the executions systems must inherits form ExecutionSystem abstract class
and implements run, get_status and kill methods.
to take in account in the mobyle these class must be registerd via the
decorator execution_systems.register

the class provide by mobyle will be placed in
mobyle.mobyle_execution_engine.systems

the mmobyle administrators can be extend mombyle with thier own classes
placed in execution_systems
set framework to route jobs
modify path according to new package engine
add new rst files for job_routing and execution_systems remove error
fix documentation
add mobyle2.lib dependencies as pip does not install requirements recursively
Merge branch 'develop' into feature_dispatcher
add new packages according to new code organization
Merge branch 'feature_dispatcher' of https://github.com/mobyle2/mobyle2.exec_engine into feature_dispatcher

Conflicts:
	requirements.txt
Merge branch 'develop' into feature_dispatcher
implement job routing in mobyle exec engine

add hard coded job routing conf to test all routing machinery
add system to register rules
the monitor add route to a job before to submit
fix return code for unit tests

fix the values return by unitest and exit with according value