More comments on var naming.
Bring back app freezing.
Add support for optional route parameters.

Optional portions of a route are surrounded by parens (eg. "items(/page/:page)").
Merge pull request #738 from ktusznio/optional-route-params

Add support for optional route parameters.
Revert "Add support for optional route parameters."

This reverts commit e172ae7a2089005e0d2dc79318a695964631d611.
Add previous route params. Closes gh-537, closes gh-716.
Fix tests.
Save route.previous only once. Closes gh-653.
Add support for optional route parameters.

Optional portions of a route are surrounded by parens (eg. "items(/page/:page)").
Merge pull request #741 from ktusznio/optional-route-params

Add support for optional route parameters.
Move changeURL command from Dispatcher into Router
fix duplicate history while url has query.
Move trailing option into Router. Use its value as default for routes. Refactoring.
Merge pull request #745 from YAndrew91/router-trailing-slashes

Move trailing option into Router. Use its value as default for routes.
Merge pull request #746 from YAndrew91/router-change-url

Move changeURL command from Dispatcher into Router
Add hint about replacing urls
Merge pull request #750 from Seldaek/patch-1

Add hint about replacing urls
Merge pull request #744 from jonakyd/topics/fix-route-with-query

fix duplicate history while url has query.