We've changed the way plugins are activated, and removed the notion of
deactivated plugins.
Now plugins activate asynchronously.
When calling a plugin, it will be activated if it wasn't, and the call will wait
for the plugin to be fully activated.
This lines up the names in the conversion plugins with the [emotionML suggested vocab](https://www.w3.org/TR/emotion-voc/#dimensions).
emoml has different names for the 4-dimensional fsre scheme and the 3-dimensional vad scheme, which this pull request has added.
I've added the "unpredictability" dimension and mapped big6:surprise to it's maximum value. The assumption is that surprise varies between 5 and 10 to be in line with the other dimensions (no such thing as negative surprise, so no values less than 5). I see that arousal also has all values >5 (so no negative arousal). Ideally, surprise mappings for V, A and D should be calculated empirically - I think there'll be some arousal and possibly slightly lowered dominance.
I wonder if we should use another colon in the emoml names, eg: "emoml:fsredim:valence" or "emoml:big6:happiness", since the [emoml suggested vocab](https://www.w3.org/TR/emotion-voc/xml) only specifies names like "happiness" in a category "big6" (ie: it's hard to know which is the category in "big6happiness").
We'd have to go through the example plugins and make sure they also conform...
open to discussion on this btw...
ps: apologies for multiple changes in this one pr..
Using this server in production is discouraged, but to implement a
proper asynchronous server with tornado/gevent every blocking call would
have to be converted to a non-blocking call.
Failing to do so causes deadlocks like senpy/senpy#35
For now, it is easier to just use the default server.
It requires pandoc, which cannot be installed with pip.
We can either link to the nbfile or convert the file
manually/automatically:
```
nbconvert SenpyClientUse.ipynb --to rst
```
