epylint.py_run was calling *epylint* script in order to
do the computation. But this was prone to failures,
in the case where we have multiple installations of Pylint,
for different Python versions, which actually led to crashes
when a Python 2's py_run call was calling epylint's belonging
to Python 3. Instead of calling epylint script directly,
we are calling Python with our known epylint code.
In order to do this, we also had to switch the shell argument
to False.
Closes#441
This gets rid of a potential issue which can occur if epylint was calling pylint
with lint.py instead. When this was happening, the first entry of sys.path would
have been the directory of pylint which contains lint.py. At the same time, if
someone analyzes, with epylint, a file that contains an import of a module,
and that module has the same name as one of the modules that are coming along
with pylint's lint.py, then instead of importing the module from site-packages,
the pylint's module would have been imported instead.
Close#920
