[ENHANCEMENT] Add auto-completion to the friendly REPL

[mardukbp]

Is your feature request related to a problem? Please describe.
Not having auto-completion is unfriendly.

Describe the solution you'd like
The friendly REPL should autocomplete its own commands as well as functions from the modules currently loaded.

Describe alternatives you've considered
None

Additional context
ipython has awesome autocompletion. Could it be possible to reuse it?

[aroberge]

This is out of scope. Instead of adding IPython to friendly, friendly can be added to IPython. Simple type

from friendly.ipython import *

after starting an IPython repl and you get all the nice feature of IPython enhanced by friendly. This approach makes it possible in theory for other "nice REPL" (ptpython, bpython, etc.) to use friendly, so that friendly does not have to worry about trying to have the best REPL with all desired features.

Furthermore, this avoids increasing significantly the number of dependencies, and the problems that come with ensuring compatibilities with all versions.

[mardukbp]

Perfect! Thanks! You are absolutely right.