Add man page for geoclue configuration file

Change in meson.build to build geoclue.5 man page from geoclue.5.in

Fixes #49
4 jobs from master in 11 minutes and 7 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #179192
ubuntu-16.04

00:02:53

passed #179193
ubuntu-17.10

00:03:46

passed #179194
ubuntu-18.04

00:02:55

passed #179195
ubuntu-18.04-no-backend

00:02:53