Added decimal support, changed implementation syntax

[HenryP3]

With this new decimal support the implementation of money mask that was:

<input v-model="price" v-mask="'money'"/>

Should be now:

<template>
   <input v-model="price" v-mask="money"/>
</template>
<script>
   [...]
   export default {
      data () {
         return {
            price: null,
            money: {
               mask: 'money',
               precision: 2 // defines the number of zeroes after the decimal separator
            }
         }
      }
   }
</script>