Packaging: fix and override more Lintian warnings

Fixes:
```
W: cinnamon-common: extended-description-line-too-long
W: cinnamon-dbg: extended-description-line-too-long
E: cinnamon: description-starts-with-package-name
W: cinnamon: extended-description-line-too-long
W: cinnamon: embedded-javascript-library usr/lib/cinnamon-settings/data/spices/jquery.js
E: cinnamon: pkg-has-shlibs-control-file-but-no-actual-shared-libs
W: cinnamon: postinst-has-useless-call-to-ldconfig
W: cinnamon: postrm-has-useless-call-to-ldconfig
```

Overrides:
`E: cinnamon: binary-or-shlib-defines-rpath usr/lib/cinnamon/libcinnamon.so /usr/lib/gnome-bluetooth`