qt: Fix Windows/Darwin executable metadata

.rc's should be linked into the executable directly,
not through a helper library.
Bump version numbers for 0.9.0rc1 release
qt: Add closing newline to help message

`bitcoin-qt --help` was missing a final newline.
Re-add BTC/KB in help message for `settxfee`

Commit a22eed6a got reverted in a RPC documentation update, redo it.