Add meson build configuration

Currently the editor will not work if it is not installed.

There is also a caveat about the 'data' directory which is installed
in the bin directory. This may work but does not seem ok because it is
pollution a shared bin directory and the 'data' folder may not be unique
to Lite.

src/meson.build

@@ -0,0 +1,16 @@
+lite_sources = [
+    'api/api.c',
+    'api/renderer.c',
+    'api/renderer_font.c',
+    'api/system.c',
+    'renderer.c',
+    'rencache.c',
+    'main.c',
+]
+
+executable('lite',
+    lite_sources,
+    include_directories: lite_include,
+    dependencies: [lua_dep, sdl_dep, stb_truetype_dep, libm],
+    install: true,
+)