Reorganize CANToolz modules

[DePierre]

CANToolz has a lot of awesome modules but they are all under the same directory modules, which makes it sometimes hard when you try to find a specific one.

In addition, some modules are named using a different norm than others and should IMO be renamed. For instance, I would suggest stripping the mod_ prefix of some of the modules, since it seems redundant.

I would suggest reorganizing the modules with something like:

modules/  <-- base modules will be found at the base directory (e.g. `mod_stats.py`)
    vircar/  <-- modules related to emulating virtual car
    io/  <-- modules supporting specific I/O hardware
    vendor/  <-- modules specific to physical car (i.e. `renault_twingo_pcm.py`)

By default, CANToolz would recursively look for the module the user wants to use. If more than one module with the provided name is found, then CANToolz would throw an error and ask for a more specific file. In case a name clash occurs, CANToolz will load the first module it found.

For instance:

# Loading modules/vendor/my_module.py
# If there is only one module named `my_module` under `modules/`, then everything's fine
# Otherwise, CANToolz would raise an exception when loading the configuration
load_modules = {
    'my_module': {}  
}

# Loading modules/vendor/my_module.py
# Need to be specific since modules/io/my_module.py exists as well
load_modules = {
    'vendor/my_module': {}  
}

• Rename modules to have a consistent naming convention
• Update references (e.g. Wiki)
• Categorize and reorganize existing modules following the structure described above
• Improve CANToolz module loading to recursively search modules under modules/
• Keep retro-compatibility with older configurations files

[DePierre]

The references to old modules in the Wiki have been updated. I believe that now, modules are more consistently named and organized.

Additional changes might be done in the future but it should be good enough for now to close the issue.