Misc additional features

Sorry thought I could do these in individual pull requests, but apparently not. These are mostly not interdependent so feel free to pick a choose.

* Explicit Message parameters: (2147d95)
I find it very restrictive that the rule's parameters are used for the message and there is no way to specify overt message parameters. There are many custom rules that need to specify different message parameters than rule parameters. For example, when validating that one field must be less than other, the rule parameter needs to be the selector of the other field, but the message is "{0} must be less than {1}" so the message parameters need to be something like "The minimum" and "the maximum."

* Less than/Greater than/Less than equal/Greater than equal (10a462f and 047e631)
A few additional useful rules, these are dependent on having explicit message parameters, otherwise their messages will not make sense. I also added ``convertStringToNumber`` which uses parseInt to convert strings to numbers for these rules. In our application, we support different number formats, so having a function like this which we could override would be very useful. Otherwise we'd have to implement all our own rules that relate to floats.

* Support for class-based messages (0ebd210)
I figure if you can specify a class-based rule, it makes sense to also allow a custom message for that class-based rule by class, just as you can for a custom static rule. For example, if I want to override the custom message for a rule, but I need it to be class-based so I can clone it with jQuery, there was no way of doing that.

NOTE: more features will be added to this pull request today