patch 8.1.0616: NSIS installer is outdated

Problem:    NSIS installer is outdated.
Solution:   Use modern syntax, MUI2 and make it work better. Add translations.
            (Ken Takata, closes #3501)

Author: brammool

Filelist

@@ -477,6 +477,7 @@ SRC_DOS =	\
 		nsis/gvim_version.nsh \
 		nsis/vimrc.ini \
 		nsis/README.txt \
+		nsis/lang/*.nsi \
 		uninstal.txt \
 		src/VisVim/Commands.cpp \
 		src/VisVim/Commands.h \
@@ -517,6 +518,7 @@ SRC_DOS_BIN =	\
 		src/xpm/x86/lib-vc14/libXpm.lib \
 		nsis/icons/*.bmp \
 		nsis/icons/*.ico \
+		nsis/icons/*.svg \
 
 # source files for Amiga, DOS, etc. (also in the extra archive)
 SRC_AMI_DOS =	\