gsettings-tool: warn if setting a value fails
gsettings-tool: warn if setting a value fails

eg, if the dconf backend cannot connect to dbus

https://bugzilla.gnome.org/show_bug.cgi?id=641768

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