Correctly handle spaces in local filepaths

Added xdg-open support

Updated README requirements for grip

Check if global flags exist before setting them

Handle space in filepath names; Fixes #19

Added missing link to browsers; Nit capitalization

Added bug reference links in README.md

Refactor README.md to be more clear with options

Added variable to remap ctrl-p

Fixed image rendering markdown path

Added GitHub markdown information to README

Added GitHub markdown to image preview mapping

Merge pull request #11 from oshybystyi/support-for-github-flavoured-md

Added support for github flavoured markdown

Added support for github flavoured markdown

Made temp file and toggle global variables; updated README

Merge pull request #10 from gmerzu/master

Supports global variable to set a browser

Supports global variable to set a browser

Updated README to show defaults

Fixed remove temp file bug

Moved common variables up; interoperable browsers;
Fixed unix background bug