Avoid NPE when getting params and limits
Update documentation for campaigns
Update lib version from 2.0.3 to 2.0.4
Simplify campaigns and (try to) make them thread-safe

There could be a problem when using different kinds of campaigns from the same place in an app.
That's because MCMCampaignAdapter is a singleton with a lot of state and all campaigns use it.
Simplify initialization

Now you don't have to use this call in your app:

`MalcomApplicationHelper.registerActivityLifecycleCallbacks(app, new MalcomActivityLifecycleCallbacks());`
Clarify how the banner layout should be

It should be a `RelativeLayout` inside another `RelativeLayout`.
Merge pull request #17 from MyMalcom/fix-npe-when-no-custom-params

Fix npe when no custom params and more...