Updated Fajr angle for ISNA method and Umm Al-Qura

It has come to my attention that ISNA and the Fiqh council of North America recommend 17.5 degrees instead of 15 for the Fajr angle. Source: http://www.icoproject.org/ISNA-Adopts-New-Angles-for-Fajer-and-Isha_ad-id!81-l!en.ks

My testing has shown this to be more accurate for locations in North America and we should adopt this change ASAP.