* gnu/packages/patches/rtags-separate-rct.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/code.scm (rtags): Dependencies no longer bundled.
[source]: Use tarball release. Use the patch to link rct.
Substitute corresponding headers.
[native-inputs]: Add new dependencies.
[inputs]: Likewise.
Signed-off-by: Ludovic Courtès <ludo@gnu.org>