Corner radius border (#3901)

* [Added] Native rounded corners rendering and border support for widgets

*** Feature and code based on openatv/enigma2@96719ca. Thanks to @jbleyel

* [Fixed] Build errors on PLi

lib/gdi/Makefile.inc

@@ -6,6 +6,7 @@ gdi_libenigma_gdi_a_SOURCES = \
 	gdi/accel.cpp \
 	gdi/bcm.cpp \
 	gdi/compositing.cpp \
+	gdi/drawing.cpp \
 	gdi/epng.cpp \
 	gdi/erect.cpp \
 	gdi/fb.cpp \
@@ -27,6 +28,7 @@ gdiincludedir = $(pkgincludedir)/lib/gdi
 gdiinclude_HEADERS = \
 	gdi/accel.h \
 	gdi/compositing.h \
+	gdi/drawing.h \
 	gdi/epng.h \
 	gdi/epoint.h \
 	gdi/erect.h \