Fixing Android/Java crash on boot due to missing init method (#70)

* adding extern c to library methods to fix JNI crash on init

* changed style to use ifdef cplusplus

src/Controls.cpp

@@ -36,6 +36,8 @@ using namespace ZeroTier;
 	#include <jni.h>
 #endif
 
+
+
 namespace ZeroTier
 {
 	extern NodeService *service;
@@ -153,6 +155,11 @@ int zts_start(const char *path, void (*callback)(void *), uint16_t port)
 	return retval;
 }
 
+
+#ifdef __cplusplus
+	extern "C" {
+#endif
+
 #ifdef SDK_JNI
 JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_start(
 	JNIEnv *env, jobject thisObj, jstring path, jobject callback, jint port)
@@ -379,6 +386,11 @@ JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_join(
 }
 #endif
 
+#ifdef __cplusplus
+}
+#endif
+
+
 int zts_leave(const uint64_t nwid)
 {
 	Mutex::Lock _l(serviceLock);
@@ -617,6 +629,9 @@ int zts_get_all_network_details(struct zts_network_details *nds, int *num)
 #ifdef SDK_JNI
 #endif
 
+
+
+
 void zts_delay_ms(long interval_ms)
 {
 #if defined(__WINDOWS__)
@@ -627,3 +642,7 @@ void zts_delay_ms(long interval_ms)
 	nanosleep(&sleepValue, NULL);
 #endif
 }
+
+
+
+