add build conf for win and osx

not sure if they totally work - but based on ci scripts and build
scripts that peolpe do use.

confs/osx.sh

@@ -0,0 +1,6 @@
+#!/bin/sh -e
+meson -Dsystemd=false -Dv4l2=false -Davahi=false -Deeze=false -Dx11=false \
+-Dopengl=full -Dcocoa=true -Dnls=false \
+-Demotion-loaders-disabler=gstreamer1,libvlc,xine \
+-Decore-imf-loaders-disabler=scim,ibus \
+ $@ . build

confs/windows.sh

@@ -0,0 +1,6 @@
+#!/bin/sh -e
+meson -Dsystemd=false -Dv4l2=false -Davahi=false -Deeze=false -Dx11=false \
+-Dopengl=none -Dpulseaudio=false -Dlibmount=false -Dfribidi=false \
+-Devas-loaders-disabler=pdf,ps,raw,svg,rsvg,json,tga,tgv \
+-Decore-imf-loaders-disabler=xim,ibus,scim \
+ $@ . build