Update browser start process error message

Update pager to use stdin

Add browser package

Adds ability to open urls with the user's configured browser.

Update find.Executable to ignore os.ErrNotExist and os.ErrPermission

Update find.Executable to temporarily ignore to readdir errors

Update find.Executable to temporarily ignore to readdir errors

Fix find.Executable not returning not found error

Fix sync/seek issues on Pager

Add pager package

Adds ability to find pagers (i.e. less)