in mpl_client.py: in read_data(): add a test to check that the io_function is...

in mpl_client.py: in read_data(): add a test to check that the io_function is a String and not a function object.
                                  The problem with function objects is that it may be a security issue. The server
	                          has a limited allowed functions (known_functions).
                                  If io_function is not a string, a WARNING is thrown and io_function
				  is replaced with io_function.__name__.
4 jobs for _compatible_ppd in 25 minutes and 18 seconds (queued for 1 second)
Name Stage Failure
failed
myplotlib_test_pep8 Test
    "__main__", mod_spec)
File "/usr/lib/python3.4/runpy.py", line 85, in _run_code
exec(code, run_globals)
File "/builds/yfournier/myplotlib/test/comp_pep8/__main__.py", line 1, in <module>
from __init__ import *
File "/builds/yfournier/myplotlib/test/__init__.py", line 1, in <module>
from .. import D_HIERARCHY
SystemError: Parent module '' not loaded, cannot perform relative import
ERROR: Job failed: exit code 1
failed
myplotlib_test_mytool Test
_set_rawdata_local -> set_rawdata
_update_local -> update
_initialize_extra_local -> _initialize_extra
_plot_local -> plot
_reset_local -> reset
CONTEXT: local
TkAgg
/usr/bin/python3: Error while finding spec for 'tests.__main__' (<class 'ImportError'>: cannot import name 'MyWin'); 'tests' is a package and cannot be directly executed
ERROR: Job failed: exit code 1