Bash completions - Fix use of complete -p

[tseeker]

• When completions are generated, complete -p should not be used if whatever is being completed could be interpreted as an option to complete.

• When there is no specific completion and complete -p '' has to be used, reinject the actual command into the output

This should fix issue #21 and an undetected issue with trying to complete after a string that starts with a dash.

[lincheney]

i've fixed this via https://github.com/lincheney/fzf-tab-completion/commit/c4685706401b566747e88269dc4cf9eee9079af1 instead can trigger this with e.g.

-onoquote <TAB>