Fix compile errors and warnings

Fix these errors/warnings:

(emacs-version)
"GNU Emacs 24.3.91.1 (x86_64-apple-darwin, NS apple-appkit-1038.36)
 of 2014-05-12 on bob.porkrind.org"

In omnisharp-add-reference:
omnisharp.el:565:23:Error: `add-to-list' can't use lexical var `tmp-params';
    use `push' or `cl-pushnew'
In omnisharp--choose-quickfix-ido:
omnisharp.el:1713:1:Warning: Lexical argument shadows the dynamic variable t
omnisharp.el:1713:1:Warning: Unused lexical argument `omnisharp-navigate-to-solution-member'
omnisharp.el:1714:42:Error: Invalid lambda variable t
In omnisharp-navigate-to-region:
omnisharp.el:1759:8:Warning: function `omnisharp-navigate-to-region' defined
    multiple times in this file
omnisharp.el:1775:8:Warning: function omnisharp-navigate-to-region used to
    take 0-1 arguments, now takes 0
omnisharp.el:1775:8:Warning: function `omnisharp-navigate-to-region' defined
    multiple times in this file
In omnisharp-start-omnisharp-server:
omnisharp.el:1846:4:Warning: misplaced interactive spec: `(interactive "fStart
    OmniSharpServer.exe for solution: ")'
In end of data:
omnisharp.el:1943:1:Warning: the function `messge' is not known to be defined.