New spf13-vim option, formatting, solarized if statement fix

These three commits:
* Add a new spf13 option (`g:spf13_clear_search_highlight`) to switch between `<leader>/` performing either `:set invhlsearch` or `:nohlsearch`
* Fix a solarized colorscheme if statement error (probably from some previous merge conflict from way back)
* General formatting updates