Added EFL copyright header

Fixes #492
Merge pull request #493 from singingwolfboy/chanlogs-header

Added EFL copyright header, closes #492
[core] Check if running with root privileges

* If running as root, print an error message and exit. This check will
not work on Windows.
Merge pull request #495 from Erethon/feature-check-root

[core] Check if running with root privileges
Rework track_modes
Remove errant prints
Add an `.is_nick()` function to the Nick class

Enables easier checking for whether an identifier is a nick or a
channel. Closes #281.
Release version 4.3.0
[__init__] Add -git to version number
[calc] Update unit tests to accept new format from WA.
[core] Improve command match regexp.

- Someone broke the command regexp by using prefix r"\.|\!". It didn't work
  as expected and instead split the whole regexp into two. Adding a
  non-capturing group around regexp should avoid this in the future.
slower channel joins on start to avoid flooding

throttling channel joins on start up are optional.
no throttling of channel joins on start up will be done if the core option 'throttle_join' is not configured.
Update currency.py

Stops the "TypeError: expected string or buffer (source unknown)" error when typing .cur and having no arguments supplied.

Quite the issue in my channel, apparently.
Merge pull request #500 from ncolton/throttle_join_on_start

slower channel joins on start to avoid flooding
Merge pull request #506 from HarinderToor/patch-1

[currency]Handle the error when no input parameters are specified.
[chanlogs] Don't hardcode home directory

Fixes #496
[youtube] Fix unicode errors
[Many modules] Add unicode_literals import

Also add #coding: utf8 line

This is probably going to force a lot of errors up, but they were
already hiding there anyway.
[ipython] Add ipython module

This module allows you to open an IPython console in module context.
If you want to debug willie in real time, or experiment with the API given to
modules, this module is for you.