Fix unexpected parent form submitting
Fix unexpected parent form submitting

Fixed submiting the parent form when a grid is inside one.
By default the buttons are of type SUBMIT. So changed them to type BUTTON. All changed buttons works with the onclick event, so this change should not break anything.
See issue #1644
Ebiroll/w2ui,ceedriic/w2ui,vitmalina/w2ui,cristianofx/w2ui,ceedriic/w2ui,ceedriic/w2ui,ceedriic/w2ui,aadrian/w2ui,Ebiroll/w2ui,Ebiroll/w2ui,aadrian/w2ui,aadrian/w2ui,Ebiroll/w2ui,aadrian/w2ui,cristianofx/w2ui,mpf82/w2ui,vitmalina/w2ui,mpf82/w2ui,vitmalina/w2ui,ceedriic/w2ui,mpf82/w2ui,ceedriic/w2ui,mpf82/w2ui,aadrian/w2ui,mpf82/w2ui,Ebiroll/w2ui,vitmalina/w2ui,Ebiroll/w2ui,mpf82/w2ui,cristianofx/w2ui,cristianofx/w2ui,aadrian/w2ui,cristianofx/w2ui,mpf82/w2ui,vitmalina/w2ui,Ebiroll/w2ui,aadrian/w2ui,vitmalina/w2ui,cristianofx/w2ui,vitmalina/w2ui,ceedriic/w2ui,cristianofx/w2ui