Fix order of arguments for PluginClass.constructor

[higuri]

Short description of changes:

Before

• The PluginClass (base class defined in src/wavesurfer.js) has constructor(ws, params)
• *Plugin (concrete classes defined in src/plugin/*.js) have constructor(params, ws)
• The WaveSurfer object instantiates plugins with new *Plugin(params, ws)

After

• The PluginClass has constructor(params, ws)

Breaking in the external API:

None

Breaking changes in the internal API:

None

Todos/Notes:

None

Related Issues and other PRs:

None

[coveralls]

Coverage decreased (-0.4%) to 69.54% when pulling f7b3a89 on higuri:patch-1 into c0a802a on katspaugh:master.

[higuri]

Now I reviewed these changes and I came to think that it is better to change concrete Plugin classes instead of the base Plugin class. I mean constructor(ws, params) is better than constructor(params, ws), because params is an optional argument that can be omitted.

Is it okay if I change all constructor of concrete Plugin classes and the line that instantiates them?
I'm sorry for this poor PR. 😓

[thijstriemstra]

@higuri

I came to think that it is better to change concrete Plugin classes instead of the base Plugin class.

I'm not sure, your fix looks ok to me. In the end it's not going to matter much what the var is called, javascript will not treat them differently, no matter what they're called.

[higuri]

Then, would you merge the current commit?

The motivation of this PR is that those who make new plugins may implement their constructors which don't work as intended, since the constructor of the plugin base class is defined differently from the actual calling way.
This can be solved with the current commit, so it is okay to keep it.

[thijstriemstra]

Thanks!