Add VERSION file, preset DTD, and .cfl version-compatibility check

CMakeLists.txt

@@ -70,6 +70,14 @@ target_compile_definitions(ChromaFlock PUBLIC
     JUCE_MODAL_LOOPS_PERMITTED=0
 )
 
+# Inject the version from the VERSION file into a generated header.
+file(READ "${CMAKE_CURRENT_SOURCE_DIR}/VERSION" CHROMAFLOCK_VERSION_RAW)
+string(STRIP "${CHROMAFLOCK_VERSION_RAW}" CHROMAFLOCK_VERSION)
+configure_file("${CMAKE_CURRENT_SOURCE_DIR}/Source/Version.h.in"
+               "${CMAKE_CURRENT_BINARY_DIR}/Generated/Version.h" @ONLY)
+
+target_include_directories(ChromaFlock PRIVATE "${CMAKE_CURRENT_BINARY_DIR}/Generated")
+
 target_link_libraries(ChromaFlock PRIVATE
     ChromaFlockBinaryData
     juce::juce_audio_basics

ChromaFlockPatch.dtd

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ChromaFlock Preset File Format DTD
+  ==================================
+  This DTD defines the structure of a ChromaFlock (.cfl) preset file.
+
+  Compatibility is governed by the "version" attribute on the root
+  <ChromaFlockPatch> element:
+
+    - version 1.0  : file-format version, compatible with ChromaFlock 0.1
+    - A .cfl whose version does NOT match the running ChromaFlock version
+      will still be loaded when possible, but the user is shown a warning
+      that the preset may not sound as intended.
+
+  Changelog:
+    1.0  (ChromaFlock 0.1)  Initial preset format.
+-->
+<!ELEMENT ChromaFlockPatch (PARAM*)>
+
+<!ATTLIST ChromaFlockPatch
+    version     CDATA #REQUIRED
+    generator   CDATA #IMPLIED
+>
+
+<!ELEMENT PARAM EMPTY>
+
+<!ATTLIST PARAM
+    id      CDATA #REQUIRED
+    value   CDATA #REQUIRED
+>

Source/Version.h.in

@@ -0,0 +1,3 @@
+#pragma once
+// Generated by CMake from the VERSION file. Do not edit manually.
+#define CHROMAFLOCK_VERSION "@CHROMAFLOCK_VERSION@"

VERSION

@@ -0,0 +1 @@
+0.1