Add MAL_NO_DEVICE_IO option.

This option disables device playback and capture. This is useful if you
only need mini_al's decoding and/or decoding APIs.

tests/mal_no_device_io.c

+// Just a simple test to check that MAL_NO_DEVICE_IO compiles.
+
+#include "../extras/dr_flac.h"
+#include "../extras/dr_mp3.h"
+#include "../extras/dr_wav.h"
+
+#define MAL_NO_DEVICE_IO
+#define MINI_AL_IMPLEMENTATION
+#include "../mini_al.h"
+
+int main(int argc, char** argv)
+{
+    (void)argc;
+    (void)argv;
+
+    mal_result result = MAL_ERROR;
+
+    mal_dsp_config dspConfig = mal_dsp_config_init_new();
+    mal_dsp dsp;
+    result = mal_dsp_init(&dspConfig, &dsp);
+    
+    mal_decoder_config decoderConfig = mal_decoder_config_init(mal_format_unknown, 0, 0);
+    mal_decoder decoder;
+    result = mal_decoder_init_file("res/sine_s16_mono_48000.wav", &decoderConfig, &decoder);
+
+    return result;
+}
+
+#define DR_FLAC_IMPLEMENTATION
+#include "../extras/dr_flac.h"
+#define DR_MP3_IMPLEMENTATION
+#include "../extras/dr_mp3.h"
+#define DR_WAV_IMPLEMENTATION
+#include "../extras/dr_wav.h"

tests/mal_test_0.vcxproj

@@ -270,6 +270,7 @@
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</ExcludedFromBuild>
     </ClCompile>
+    <ClCompile Include="mal_no_device_io.c" />
     <ClCompile Include="mal_profiling.c">
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
@@ -287,12 +288,12 @@
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</ExcludedFromBuild>
     </ClCompile>
     <ClCompile Include="mal_test_0.c">
-      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">false</ExcludedFromBuild>
-      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM'">false</ExcludedFromBuild>
-      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">false</ExcludedFromBuild>
-      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|ARM'">false</ExcludedFromBuild>
-      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">false</ExcludedFromBuild>
-      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">false</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|ARM'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</ExcludedFromBuild>
     </ClCompile>
     <ClCompile Include="mal_test_0.cpp">
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>

tests/mal_test_0.vcxproj.filters

@@ -30,6 +30,9 @@
     <ClCompile Include="mal_resampling.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="mal_no_device_io.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\mini_al.h">