Cannot build and link iup.rc for Windows

[thelink2012]

This is not really a issue with iup-rust but rust-lang itself that closely affects this project. When the issue gets off rust-lang the build process here should be updated.

Related rust-lang issues: rust-lang/rfcs#721 rust-lang/cargo#544 - Passing the .res objet file through link-args would help. rust-lang/rust#25030 - windres.exe is required to build the .rc source into the .res object file (maybe, just maybe, this one should be addressed by the C toolchain not the rust toolchain).

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Rust build system (cargo / attributes) cannot add object files to be built into the output binary, thus it is not possible to include the iup.res file required by iup on static builds for Windows as instructed here:

The iup.rc resource file (or a custom version) should be included in the application's project/makefile so that some icons and cursors can be used when not using the DLLs and to enable Windows Visual Styles. iup.rc is located in "/etc" folder of the distribution.

Thus it's necessary to link to a dynamic iup library on Windows to get along