Fix previousInclude and previousExclude checks.

[ellisio]

The current implementation requires you to always define :include AND :exclude for search to work. For example, if you do the following:

<picker
    set="apple"
    :emoji-size="16"
    :per-line="12"
    :exclude="['custom']"
    @click="addEmoji">
</picker>

Then attempt to search, you will receive the following JS error:

vendor.js:11692 Uncaught TypeError: Cannot read property 'sort' of undefined
    at Object.search (vendor.js:11692)
    at VueComponent.onInput (vendor.js:11532)
    at boundFn (vendor.js:93445)
    at HTMLInputElement.invoker (vendor.js:95018)

By doing the following, the error goes away:

<picker
    set="apple"
    :emoji-size="16"
    :per-line="12"
    :include="[]"
    :exclude="['custom']"
    @click="addEmoji">
</picker>

There is no reason to require the developer to have the empty :include just to get searching working. So this fix will break the checks apart for previousInclude and previousExclude to resolve this issue.

[jm-david]

Looks great, thank you :)