Added meson build files and manifests for dlls.

Works, builds both native linux and cross-compiles mingw-w64 variants.
Need to work out copying appropriate dlls into the mkxp runtime folder.

Signed-off-by: Marty Plummer <ntzrmtthihu777@gmail.com>

tools/xxd.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+# meson resolves paths such as processing assets/icon.png's command line
+# ends up being `xxd -i ../assets/icon.png icon.png.xxd`, resulting in a
+# prefix of `___` on all variable names. We postprocess xxd with sed for
+# now in order to have proper variable names.
+# ./xxd.sh /path/to/xxd /path/to/sed infile outfile
+
+$1 -i $3 $3.tmp
+$2 's:___::g' $3.tmp > $4
+rm $3.tmp