Save Site as template while Publishing Feature is activated

Problem

Saving a Site Template with an activated Publishing Feature is impossible in SharePoint 2013 (menu link missing).

When using the direct browser link (which worked perfectly in SharePoint 2010) http://YourSharePointSite/_layouts/15/savetmpl.aspx, you get the error The “Save site as template” action is not supported on this site.

Solution 

Modify the SaveSiteAsTemplateEnabled property in your SPWeb object via PowerShell.

# Store your Site in a variable:
$SiteToModify = Get-SPWeb http://YourSharePointSite

# Display the current value of the property:
$SiteToModify.AllProperties["SaveSiteAsTemplateEnabled"]

# Set the property to true:
$SiteToModify.AllProperties["SaveSiteAsTemplateEnabled"] = "true"
$SiteToModify.Update()

When now trying the savetmpl.aspx link again, you can save your template:
http://YourSharePointSite/_layouts/15/savetmpl.aspx