[v0.9.x] Queue for plugin installation

[thymian]

I just installed a fresh 0.9.18 on my pi. I went into the plugin section and scrolled through the whole list. Sadly I cant go though it and click on every plugin I want to install, because I always have to wait until the last one is installed.

Plugin-Installations would be more intuitive if one:

1. present a bigger popup "Plugin is installing, please wait" or 2) BETTER: create a queue for every plugin where i pressed "Install" and install them one after another.

[mwittig]

Agree, this should be improved. If I try to install another plugin, say pimatic-edimax, while a plugin installation is in progress I get the following error:

error [pimatic]: Error installing plugin pimatic-edimax: undefined