Allow integers as parameters

[bterkuile]

At the moment implementing structures like:

{{#if (gt a b)}}
A is greater than b
{{/if}}

is possible. However using numbers in the templates is not.
This would be something like:

{{#if (gt my_value 10000)}}
Wow! What a great value!
{{/if}}

Therefore integers (and future floats) should be able to pass as parameters.