gsettings m4: check for .xml in src/builddir
gsettings m4: check for .xml in src/builddir

This checks for the .gschema.xml file in the srcdir and builddir and
runs the schema validation on which one it finds.  This handles
non-srcdir builds in both cases: .gschema.xml is in the tarball and
.gschema.xml is generated.

ieei/glib,tamaskenez/glib,cosimoc/glib,djdeath/glib,ieei/glib,iConsole/Console-OS_external_bluetooth_glib,tchakabam/glib,krichter722/glib,gale320/glib,pstglia/platform-external-bluetooth-glib,justinkb/aosp-bluez.glib,cention-sany/glib,tchakabam/glib,endlessm/glib,krichter722/glib,cosimoc/glib,ieei/glib-old-android,bratsche/glib,zsx/glib,justinkb/aosp-bluez.glib,djdeath/glib,dicer/android_external_glib,cosimoc/glib,krichter722/glib,dicer/android_external_glib,cosimoc/glib,johne53/MB3Glib,tamaskenez/glib,endlessm/glib,bratsche/glib,dicer/android_external_glib,iConsole/Console-OS_external_bluetooth_glib,lukasz-skalski/glib,endlessm/glib,djdeath/glib,gale320/glib,01org/android-bluez-glib,darren-clark/android_platform_external_bluetooth_glib,pstglia/external-bluetooth-glib,01org/android-bluez-glib,cosimoc/glib,MathieuDuponchelle/glib,mzabaluev/glib,pstglia/external-bluetooth-glib,cention-sany/glib,iConsole/Console-OS_external_bluetooth_glib,zsx/glib,ahmedammar/platform_external_gst_glib,bluez-android/glib,ieei/glib-old-android,tchakabam/glib,bratsche/glib,Distrotech/glib,iConsole/Console-OS_external_bluetooth_glib,lukasz-skalski/glib,ieei/glib-old-android,antono/glib,tchakabam/glib,ahmedammar/platform_external_gst_glib,pstglia/platform-external-bluetooth-glib,antono/glib,pstglia/external-bluetooth-glib,endlessm/glib,cention-sany/glib,Distrotech/glib,justinkb/aosp-bluez.glib,darren-clark/android_platform_external_bluetooth_glib,johne53/MB3Glib,darren-clark/android_platform_external_bluetooth_glib,bratsche/glib,tchakabam/glib,cention-sany/glib,01org/android-bluez-glib,ieei/glib,mzabaluev/glib,endlessm/glib,tamaskenez/glib,antono/glib,ieei/glib-old-android,antono/glib,pstglia/external-bluetooth-glib,dicer/android_external_glib,Distrotech/glib,mzabaluev/glib,justinkb/aosp-bluez.glib,zsx/glib,darren-clark/android_platform_external_bluetooth_glib,djdeath/glib,pstglia/platform-external-bluetooth-glib,tamaskenez/glib,krichter722/glib,iConsole/Console-OS_external_bluetooth_glib,lukasz-skalski/glib,gale320/glib,01org/android-bluez-glib,01org/android-bluez-glib,dicer/android_external_glib,ieei/glib,johne53/MB3Glib,pstglia/platform-external-bluetooth-glib,ahmedammar/platform_external_gst_glib,bluez-android/glib,mzabaluev/glib,darren-clark/android_platform_external_bluetooth_glib,Distrotech/glib,lukasz-skalski/glib,bluez-android/glib,krichter722/glib,Distrotech/glib,johne53/MB3Glib,MathieuDuponchelle/glib,djdeath/glib,bluez-android/glib,bluez-android/glib,gale320/glib,justinkb/aosp-bluez.glib,MathieuDuponchelle/glib,zsx/glib,johne53/MB3Glib,MathieuDuponchelle/glib,tamaskenez/glib,pstglia/platform-external-bluetooth-glib,pstglia/external-bluetooth-glib,gale320/glib,ahmedammar/platform_external_gst_glib,johne53/MB3Glib,mzabaluev/glib,lukasz-skalski/glib,ieei/glib,cention-sany/glib,MathieuDuponchelle/glib