Remove redundant virtual packages

As PROVIDES can be used to replace real packages now, we don't need the
virtual packages as workaround anymore. This also means that the providing
packages don't need to be added to site.mk explicitly anymore when the
default provider is used.

docs/site-example/site.mk

@@ -9,7 +9,6 @@ GLUON_SITE_PACKAGES := \
 	gluon-autoupdater \
 	gluon-config-mode-autoupdater \
 	gluon-config-mode-contact-info \
-	gluon-config-mode-core \
 	gluon-config-mode-geo-location \
 	gluon-config-mode-hostname \
 	gluon-config-mode-mesh-vpn \
@@ -22,7 +21,6 @@ GLUON_SITE_PACKAGES := \
 	gluon-mesh-batman-adv-15 \
 	gluon-mesh-vpn-fastd \
 	gluon-radvd \
-	gluon-setup-mode \
 	gluon-status-page \
 	haveged \
 	iwinfo

package/gluon-config-mode-autoupdater/Makefile

@@ -14,7 +14,7 @@ define Package/gluon-config-mode-autoupdater
   SECTION:=gluon
   CATEGORY:=Gluon
   TITLE:=Config Mode: Let the user know whether the autoupdater is enabled or not
-  DEPENDS:=gluon-config-mode-core-virtual +gluon-autoupdater
+  DEPENDS:=+gluon-config-mode-core +gluon-autoupdater
 endef
 
 define Build/Prepare

package/gluon-config-mode-contact-info/Makefile

@@ -14,7 +14,7 @@ define Package/gluon-config-mode-contact-info
   SECTION:=gluon
   CATEGORY:=Gluon
   TITLE:=Allows the user to provide contact information to be distributed in the mesh
-  DEPENDS:=gluon-config-mode-core-virtual +gluon-node-info
+  DEPENDS:=+gluon-config-mode-core +gluon-node-info
 endef
 
 define Package/gluon-config-mode-contact-info/description

package/gluon-config-mode-core/Makefile

@@ -17,8 +17,7 @@ define Package/gluon-config-mode-core
   SECTION:=gluon
   CATEGORY:=Gluon
   TITLE:=Configuration wizard for user friendly setup of new mesh nodes
-  DEPENDS:=gluon-setup-mode-virtual +gluon-web-theme +gluon-lock-password +pretty-hostname
-  PROVIDES:=gluon-config-mode-core-virtual
+  DEPENDS:=+gluon-setup-mode +gluon-web-theme +gluon-lock-password +pretty-hostname
 endef
 
 define Build/Prepare

package/gluon-config-mode-geo-location/Makefile

@@ -14,7 +14,7 @@ define Package/gluon-config-mode-geo-location
   SECTION:=gluon
   CATEGORY:=Gluon
   TITLE:=Set geographic location of a node
-  DEPENDS:=gluon-config-mode-core-virtual +gluon-node-info
+  DEPENDS:=+gluon-config-mode-core +gluon-node-info
 endef
 
 define Build/Prepare

package/gluon-config-mode-hostname/Makefile

@@ -14,7 +14,7 @@ define Package/gluon-config-mode-hostname
   SECTION:=gluon
   CATEGORY:=Gluon
   TITLE:=Set the hostname
-  DEPENDS:=gluon-config-mode-core-virtual
+  DEPENDS:=+gluon-config-mode-core
 endef
 
 define Build/Prepare

package/gluon-config-mode-mesh-vpn/Makefile

@@ -14,7 +14,7 @@ define Package/gluon-config-mode-mesh-vpn
   SECTION:=gluon
   CATEGORY:=Gluon
   TITLE:=Toggle mesh-vpn and bandwidth limit
-  DEPENDS:=gluon-config-mode-core-virtual +gluon-mesh-vpn-core
+  DEPENDS:=+gluon-config-mode-core +gluon-mesh-vpn-core
 endef
 
 define Build/Prepare

package/gluon-setup-mode/Makefile

@@ -16,7 +16,6 @@ define Package/gluon-setup-mode
   CATEGORY:=Gluon
   TITLE:=Setup mode
   DEPENDS:=+gluon-core +gluon-web +ubus +uhttpd +dnsmasq
-  PROVIDES:=gluon-setup-mode-virtual
 endef
 
 define Package/gluon-setup-mode/description

package/gluon-web-admin/Makefile

@@ -18,7 +18,7 @@ define Package/gluon-web-admin
   SECTION:=gluon
   CATEGORY:=Gluon
   TITLE:=Web-based simple administration interface for mesh nodes
-  DEPENDS:=gluon-config-mode-core-virtual +pretty-hostname
+  DEPENDS:=+gluon-config-mode-core +pretty-hostname
 endef
 
 define Build/Prepare