This simplifies name handling in the situation where a library and a
client are both verified projects, extracting separately, and linking
together.

Consider Library.A.Base1.fst and Library.A.Base2.fst, extracted with:

-bundle Library.A.Base1+Library.A.Base2=[rename=Library_A,rename-prefix]

The client, in order to use the library, passes `-library Library.*`,
but without any further options, must also replicate the bundle above in
order to generate code that references Library_A_foobar instead of
Library_A_Base1_foobar; note that the latter would be a linking error.

This is onerous: the library must export its bundle options in a format
consumable by the client; furthermore, the client is bound by the bundle
choices of the library and has no way of grouping, say, in Library.h all
of the `extern` declarations pertaining to Library while also at the
same time respecting the renamings enabled by rename-prefix.

This PR offers an alternate route: the library records in a
krmlrenamings.h file all of the name changes that deviate from the
default, e.g.

```
```

This allows the client to replace a litany of bundle/rename options with
a mere `-add-include '"library/clients/krmlrenamings.h"'`