[modificarPrecios] validaciones
Merge branch 'develop' of github.com:jotaemepereira/PIS-GR4-2014 into develop

Conflicts:
	sources/Prototipos/Java/DUSA/WebContent/stock/modificarPrecios.xhtml
Merge branch 'develop' of github.com:jotaemepereira/PIS-GR4-2014 into develop