use FSEventStreamSetDispatchQueue instead of deprecated FSEventStream…

…ScheduleWithRunLoop (#62)

update AUTHORS file

Cannot use nil for CFType (Go 1.10+)

fixes #40

Cannot use nil for CFType (Go 1.10+), round 2

reducing code changes between Go versions

conversions can occur in older Go versions too

extract eventIDSinceNow constant to other files

Go-version specific files.

reworks #34 which resolves int overflow #31

minimize code differences between Go versions

Work around bizarre bugs in 1.10.3 (not 1.10.4)

golang/go#24161

use C.kCFAllocatorDefault instead of C.CFAllocatorRef(0)

thanks to @havoc-io for the tip

reduce duplication between go 1.10 before/after

thanks to C.kCFAllocatorDefault change