[WebUI] disable quick look and message when processes stats is disable

[WebUI] filesystem free space

Add "Show filesystem free space"
strict compliance shortcuts

[WebUI] Fix layout of the help page

[WebUI] fix io write in the process list

[Web UI] Quicklook plugin

[Web UI] Fix memswap plugin displaying mem values

[Web UI] Reorder top plugins like in the curse interface

[Web UI] Update keyboard shortcuts

* remove all shortcuts not implemented yet in web UI
* implement show/hide Docker stats shortcut
* implement show/hide processes stats

[Web UI] Network cumulative/combination

Handle cumulative and combination mode for network I/O
Fix shortcuts for cumulative and combination
Use bit/s for network I/O

Hide empty sensors in web ui

[Web UI] Big refactoring

Move logic from controller and views to the new services GlancesStats and GlancesPlugins : GlanceStats load data from api and set data in plugins. Plugins are responsible for transforming data for the view.
GetAlert is now in GlancesPlugin
Use view data instead of getAlert when is possible
Remove directives for monitor plugin

[Web UI] Fix debug mode