Add config file parsing

Checks for a gamemode.ini in /usr/share/gamemode/ (or in the cwd for debugging)

	Currently allows for blacklisting and whitelisting clients based on rudimentary needle-haystack executable name checks

	See the example/gamemode.ini file for expected syntax

	Using the BSD licensed inih library (with additional meson.build file)

daemon/daemon_config.h

@@ -0,0 +1,72 @@
+/*
+
+Copyright (c) 2017, Feral Interactive
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice,
+   this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+ * Neither the name of Feral Interactive nor the names of its contributors
+   may be used to endorse or promote products derived from this software
+   without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+ */
+#pragma once
+
+#include <stdbool.h>
+
+/*
+ * Opaque config context type
+ */
+typedef struct GameModeConfig GameModeConfig;
+
+/*
+ * Initialise a config
+ */
+GameModeConfig *config_create(void);
+
+/*
+ * Initialise a config
+ * Must be called before using any config later config functions
+ */
+void config_init(GameModeConfig *self);
+
+/*
+ * Reload a config from disk
+ * Thread safe to call
+ */
+void config_reload(GameModeConfig *self);
+
+/*
+ * Destroy a config
+ * Invalidates the config
+ */
+void config_destroy(GameModeConfig *self);
+
+/*
+ * Get if the client is in the whitelist
+ * returns false for an empty whitelist
+ */
+bool config_get_client_whitelisted(GameModeConfig *self, const char *client);
+
+/*
+ * Get if the client is in the blacklist
+ */
+bool config_get_client_blacklisted(GameModeConfig *self, const char *client);