Screen-brightness-control

* Added `method` kwarg to brightness methods so that you can choose how the brightness is adjusted. On windows the options are `'wmi'` and `'vcp'` and on linux they are `'light'`, '`xrandr'` and `'xbacklight'`
* Added method command line arg
* Merged pull request from `lcharles` 2 to add top-level function `list_monitors` (Windows only), add a command line option for this and add a function in the windows module called `list_monitors_with_method`, which returns list of pairs of display names and their methods
* Fixed the `XRandr.get_brightness` function returning the wrong type

* Updated FAQ section of README

* Updated README with an FAQ section
* Minor adjustment to `fade_brightness`

* Fixed `get_brightness` attribute errors for Windows
* The Windows version will now set the brightness for ALL wmi brightness methods (not just the first one)
* If there are multiple brightness methods then `get_brightness` will return a list of brightness values
* Added a copy of the MIT license to the files

* Made some type conversions in `set_brightness` ever so slightly more reliable
* Added `max_value` kwarg to `get_brightness`
* Fixed a logic error in `get_brightness`
* Fixed rounding error in `get_brightness`

Patch 1:
* Removed debug print statements

Patch 2:
* Fixed not returning false upon failure on Windows
* If fade_brightness cannot set the brightness it exits the for loop