Small build fixes in preparation for dependencies and c-i work

A few more small changes necessary for the new dependencies.
- Fix OSX packaging when Qt is static
- Fix Linux build when Qt is static
- Fix 'make deploy' when make has not been run yet
- Fix the annoying fpic+mingw warnings (closes #3607)
- Don't let libtool embed rpath in Linux

Other than the fixed warning spew with mingw, these should all be no-ops for anyone building as usual.