Link libraries recursively

[virtuald]

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Need to think through the right way to do this. Currently, we have to add depends for everything in the chain, which is a bit obnoxious.

Probably should look at cmake to see what they do -- for cmake target_link_libraries has a concept of PRIVATE/PUBLIC/INTERFACE options, where PUBLIC/INTERFACE options are inherited by children and PRIVATE are only used by the target itself and not its dependencies.