Add support to see further in the future

[calhix]

Currently it looks like you can see two months in the future, it would be nice to be able to see perhaps six months in the future. It may seem ridiculous but for booking vacations and such, it would be very helpful when you're picking certain flights/hotels, etc. as you need to book far out for good deals, especially some places that are very popular/high-end.

[arnowelzel]

Technically this is not a big deal - just changing a 2 to a 6 somewhere in the code. Maybe I will add a setting for this with a clear warning, if you choose more than 2 or 3 months.

However: the problem with this is, that it is just a mathematical calculation based on an average value - and this may not match the real cycles which can be shorter and longer. So if you plan anything just based on that prediction, you may be disappointed, when it is 1 or 2 weeks off - which is very likely for a time period of 5 or 6 months in the future.