Implement comparison expressions in if and unless

[askonomm]

So that something like this could be possible:

<div x:if="age > 30"></div>

or even

<div x:if "age >= allowedAge"></div>

To be able to compare between multiple vars.

Things to support could be:

• >
• <
• ==
• >=
• <=

[askonomm]

Could be cool if this could also support and and or, as well as parentheses for nested expressions, e.g

age >= (baseAge + 10) and userRole == 'user'