Add support for matching parameters with current()

[bakerkretzmar]

This PR adds the ability to pass a second argument to current() with an object containing parameters to check in addition to the route name. Closes #211.

// Route 'events.venues.show': /events/{event}/venues/{venue}
// On https://myapp.com/events/1/venues/2

// Before
route().current() // 'events.venues.show'
route().current('events.venues.show') // true

// After
route().current('events.venues.show', { event: 1, venue: 2 }) // true
route().current('events.venues.show', { event: 2, venue: 6 }) // false

It matches query parameters too:

// On https://myapp.com/events/1/venues/2?user=Amy
route().current('events.venues.show', { event: 1, venue: 2, user: 'Amy' }) // true

current() was also updated to ignore the query string when retrieving the name of the current route:

// On https://myapp.com/events/1/venues/2?user=John

// Before
route().current() // undefined

// After
route().current() // 'events.venues.show'

This implementation has one major caveat: parameters are matched all-or-nothing, including the query string. In the future it would be great if Ziggy supported matching just some parameters, but for now it will check everything you pass in:

// On https://myapp.com/events/1/venues/2
route().current('events.venues.show', { event: 1 }) // false

// On https://myapp.com/events/1/venues/2?user=Amy
route().current('events.venues.show', { event: 1, venue: 2 }) // false

Thanks to @sbine for helping with a bunch of the regular expression stuff in here!