Returned improved crawlable feature

[laukstein]

• Improved crawlable feature turned on by default
• Fixes issue #56 rewrite /#/url to /#!/url (no more use for /#/url)
• Fixes issue #109 use .on() and .off() besides of outdated .bind() and .unbind()
• Specify plugin version also in development file
• Begin to add commented descriptions in development file