Missing boolean dependencies support

[Sami32]

Boolean dependencies are supported since RPM >= 4.13

http://rpm.org/user_doc/boolean_dependencies.html

I find this very useful, when it come to rely on a specific Java version for example, as too many Oracle, OpenJDK...savors exist and without this capability it is impossible to produce RPM builds having a great compatibility among all the Debian based Linux distributions or avoid unecessary dependencies download.