## basalt.setVariable
This stores a variable which you're able to access via xml. You are also able to add a function, which then gets called by object events created in XML.

#### Parameters: 
1. `string` a key name
1. `any` any variable

#### Usage:
* Adds a function to basalt.
```lua
basalt.setVariable("clickMe", function()
    basalt.debug("I got clicked")
end)
```
```xml
<button onClick="clickMe" text="Click me" />
```