Feature: Check for dependency requirements recursively

[ericm]

Gives user chain of dependencies when uninstalling a required program.

[ericm]

For example when i uninstall a program Y required by X, I get a message saying X: uninstalling package Y breaks dependency Y. If instead of that if yup could preemptively identify these issues and ask the user if they wish to uninstall both X and Y, this would be far more favourable. The list of deps could be found recursively or by calling pactree