Simple Audio Player - Shortcode

This plugin adds a general shortcode [audio], usable in classic Joomla articles and the native "Custom content" module, and all other third party extension using default joomla "contents events".

This shortcode display a simple Audio player that does the job, the shortcode syntax is the same as Wordpress one, thats why if you want to import Wordpress article to Joomla! this plugin is for you.

The JS librairie used is MediaElement.js.

Shortcode usage:
- Simple : [audio src="/audio.mp3"]
- Advanced : [audio src="/source.mp3" loop="on" preload="auto" autoplay="on"]

Mandatory parameter :
- src : URL of your audio file, be careful not to use the [ and ] characters in the file name

Optional parameters :
- loop : on / off = Allows for the looping of media
- autoplay : on / off = Causes the media to automatically play as soon as the media file is ready.
- preload : none / auto / metadata = Specifies if and how the audio should be loaded when the page loads, by default the audio should not be loaded when the page loads, auto = the audio should be loaded entirely when the page loads, metadata = only metadata should be loaded when the page loads.
- style : CSS code applied to the player
- background : background color of the player, various formats supported : #228CBF rgb(34, 140, 191) ou encore rgba(34, 140, 191, 0.50)
- hidden : on / off = hide the player
- showvolume : on / off = permit to show or not the volume group
- txtcolor : change text color, accept classic css colors : #f00, red, rgba(255,0,0,0.5) ..
- btcolor : change color of main buttons, black, red, green, blue or white

Underscore value = default value

If multiple players are on the same page? The autoplay is disabled, and it is impossible to play two songs simultaneously.

Version 1.5 :
 + new attribute added : "showvolume"
 + new attribute added : "txtcolor"
 + new attribute added : "btcolor"
 + update jQuery to latest version (3.2.1)
 + rewrite the way to load the main library (more efficient now)
 + CSS : removing 'box-shadow' on buttons (some templates skin all buttons..)
 + CSS : removing 'outline' on buttons focused

Version 1.4 :
 + add automatic updates
 + fix a display bug with some specific templates

Version 1.3 :
 + new global params "default width", define the default player width, even if it loads in a tab or a toggler

Version 1.2 :
 + new attribute added : "hidden"

Version 1.1 :
 + new attribute added : "background"
 + fix some bugs