GDateTime: test _format against strftime()
GDateTime: test _format against strftime()

Test g_date_time_format() against strftime().  This test found quite a
few cases of incorrect behaviour on our part (fixes already committed
for those).

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