Minor wrap_c updates

* Added remaining definitions for `uintX_t`, `intX_t` to `cl_to_jl`
* Put library name in `QuoteNode` on ccall output
* Keep track of wrapped `UnionDecl` nodes

Not sure about most of these changes, actually.

* For the `(u)intX_t` changes, it's unclear to me why these are not identified as standard `cindex` types (but I haven't looked into it that carefully).  When wrapping libav, these were needed.
* Both the function call and library name are symbols in the call to eccall.  The function name was already wrapped in a `QuoteNode`.  I found that I needed the library name to be wrapped as well, but perhaps you meant for this to be a user-defined variable?
* For `StructDecl`, keeping track of previously wrapped nodes is necessary (for libav, at least) to prevent duplicate parsing and output.  I haven't specifically run into issues with duplicates with `UnionDecl` types, but I'm assuming it's necessary here as well.  But maybe not?