Android support (#299)

* AI libs registering shenanigans on android;
* Fixed resolution aspect + mouse event scaling;
* Proper server init/deinit (through android IPC);
Enabled threaded init in CMT;
* Prevented a deadlock in logger on some devices;
* Fixed frozen intro frame after interrupting the video;
Added android progressbar displaying during initial data loading;
* Hacky fix for choppy animations during heroes movement (should look better now, but it's definitely not a good solution);
* Changes/fixes for new android launcher building process;
* Fixed app hang after getting SDL_QUIT when activity was destroyed;
* Functioanal, configurable advmap swiping support;
* VCMI changes cleanup;
Added few missing VCMI_ANDROID guards on swipe mechanics;
* Removed unneeded sleep in server startup code for android;
* Removed android ioapi hack (fixed in newest ndk);
* Removed unused android's library loading logic;
* Added android's swipe option to settings schema;
* Moved NO_STD_TOSTRING to be defined in global.h instead of build files;

lib/CAndroidVMHelper.h

@@ -0,0 +1,41 @@
+/*
+ * CAndroidVMHelper.h, part of VCMI engine
+ *
+ * Authors: listed in file AUTHORS in main folder
+ *
+ * License: GNU General Public License v2.0 or later
+ * Full text of license available in license.txt file, in main folder
+ *
+ */
+#pragma once
+
+#include <jni.h>
+#include <string>
+
+/// helper class that allows access to java vm to communicate with java code from native
+class CAndroidVMHelper
+{
+	JNIEnv * envPtr;
+	bool detachInDestructor;
+
+	jclass findClass(const std::string & name, bool classloaded);
+
+public:
+	CAndroidVMHelper();
+
+	~CAndroidVMHelper();
+
+	JNIEnv * get();
+
+	jclass findClassloadedClass(const std::string & name);
+
+	void callStaticVoidMethod(const std::string & cls, const std::string & method, bool classloaded = false);
+
+	std::string callStaticStringMethod(const std::string & cls, const std::string & method, bool classloaded = false);
+
+	static void cacheVM(JNIEnv * env);
+
+	static void cacheVM(JavaVM * vm);
+
+	static constexpr const char * NATIVE_METHODS_DEFAULT_CLASS = "eu/vcmi/vcmi/NativeMethods";
+};