New formatter option: Align in columns 'case' branches

This option allows formatting 'when' statements in two ways:

option is OFF:
<pre>when (x) { 
    parseInt(s) -> print("s encodes x") 
    else -> print("s does not encode x") 
}
</pre>
option is ON:
<pre>
when (x) { 
    parseInt(s) -> print("s encodes x") 
    else        -> print("s does not encode x") 
}
</pre>