Booking kinks: rate limits

[chibenwa]

Allow defining rate limits for booking links...

... on a per link basis
... on a global basis

Use either memory or redis rate limiters (ratelimitj?)

Limits are to be defined in configuration and should allow for several time ranges. configuration.properties

For instance:

bookingLink.rateLimits.global=1s:1000,1m:3000,1h:30000,1d:600000
bookingLink.rateLimits.perLink=1s:10,1m:30,1h:300,1d:6000

To be noted that ommiting this for the configuration means unlimited.