Prevent clap from intercepting hyphens passed to rr_opts

[NickHu]

Fixes issue #11

I took the liberty of updating all the dependencies too

[NickHu]

Now rr_opts needs to be enclosed by quotes, and the documentation/help output on this could probably be improved, but it's possible to start gdb-server with rr now (i.e. rr replay -s 1234)

[nix-shell:/tmp/cargo-rr]$ ./target/debug/cargo-rr rr replay test-2e32310c57f5ef72 "-s 1234"
Launch gdb with
  rust-gdb '-l' '10000' '-ex' 'set sysroot /' '-ex' 'target extended-remote 127.0.0.1:1234' /tmp/cargo-rr/target/rr/test-2e32310c57f5ef72/mmap_copy_5_test-2e32310c57f5ef72

[dzfranklin]

Nice catch, I'm not sure how I missed that.

Two optional positional arguments still doesn't work well. You can't do rr replay -s 1234, you have to do rr replay test-foobar -s 1234. What if it was a named argument instead, something like rr replay --rr-opts "-s 123"?

[dzfranklin]

Fixed in #14