Ability to specify which library is updated in manual sync.

## Features

Add ability to specify which library gets updated in manual sync with a new variable, library.

Default action for manual sync is all.

Usage:
```
RunScript(script.trakt,action=sync[,silent=True][,library=[all|episodes|movies]])
```
Example:
```
RunScript(script.trakt,action=sync,library=episodes)
```

The above example will trigger a sync only for tv shows.

## Changes

* Add ability to specify which library gets updated in manual sync with a new variable, library. This still checks if episode/movie sync is enabled or disabled.
* Usage: RunScript(script.trakt,action=sync[,silent=True][,library=[all|episodes|movies]])
* The variable is optional, and if omitted defaults to all.