Cannot specify an alternative browser

[Symbolics]

In some environments, the default browser, the one the user normally uses, has JavaScript and other security measures in place that mean it cannot render Plotly. In these cases, an alternative browser can be installed specifically for rendering, however open-browser is hard-coded to use explorer (on MS Windows).

One solution is to specify the browser in an init file, e.g. kai-init.lisp, like so:

(defparameter *browser* "C:\\Program Files (x86)\\Google\\Chrome\\Application\\chrome.exe")
(defparameter *browser-options* "--app=")

and then launching it like this:

(uiop:run-program #+(or win32 mswindows windows)
		      `(,*browser*
			,(concatenate 'string
				      *browser-options*
				      (namestring path-to-html)))

This also provides the ability to set browser options, like in this case where all the browser window controls are removed and only the plot is displayed.

[Symbolics]

This issue is addressed in pull request #18.

Existing functionality is unchanged by default. Chrome has been added as an alternative, along with a few common options. The additions can also support other browsers and options.