Fix issue #1301

Added a Steam sensor

Filter out AirCam models in UVC camera platform

Template helpers

The older (unsupported AirCam) models behave differently and also apparently
suffer some under the last release of the NVR that supported them. Since they
are EOL and not supported by current software, filter them out so we don't
break while trying to extract an image from them.

Fix dispatching for regular WeMo switch devices.

I only have WeMo Link and Insight devices and assumed model names of other
devices were fairly straightforward.

But it looks like the regular WeMo switch uses 'Socket' as the model name.

New template helpers now, utcnow, distance, closest

UVC Fixes, features, and tests

This adds tests for the uvc camera module. It's a good thing too,
because I found a few bugs which are fixed here as well:

 - Graceful handling of non-integer port
 - Failure to take the first host that works when probing host,internalHost
 - Failure to detect if neither of them actually work

This also converts the code to only call add_devices once with a listcomp.

The NVR tells us the admin username, but not the password for the
camera. Right now, we assume the default password, which obviously
doesn't work for people that have changed it. The uvcclient library
provides a way to set the cached admin password for a camera, which
is stored in a client-specific location. We can utilize that to
grab the password, falling back to the default if it's unset. With
this, people just need to run a command per camera to set the
admin password on their systems, if it has changed.

Added the "for" param to the conditions as well

Fix service documentation appearing for notifications

Added command_rollershutter component

Don't set Bitcoin wallet if not setup in configuration

We want the descriptions for notify.notify regardless of the name of the
exact notify service being called.

Because of problems with the Wallet part of python blockchain library (see #1242 ) , the entire Bitcoin module isn't working currently.
This change does not fix those problems but at least makes the sensor work again for people who don't need Wallet-related functionality.

It also just seems better practice to not set a wallet and call "wallet.get_balance()" when not wallet is set in configuration.

Wemo leds

Add generic TCP socket component

ZWave binary sensor support