Make public headers C99 compliant. (#186)

* Add -std=c99 and -pedantic-errors to CFLAGS.

examples/cc2538/platform/startup-gcc.c

@@ -47,7 +47,7 @@ extern uint8_t _einit_array;
 __extension__ typedef int __guard __attribute__((mode(__DI__)));
 int __cxa_guard_acquire(__guard *g) { return !*(char *)(g); }
 void __cxa_guard_release(__guard *g) { *(char *)g = 1; }
-void __cxa_guard_abort(__guard *g) {};
+void __cxa_guard_abort(__guard *g) {}
 void __cxa_pure_virtual(void) { while (1); }
 
 void IntDefaultHandler(void);

examples/posix/platform/Makefile.am

@@ -35,9 +35,9 @@ libopenthread_posix_a_CPPFLAGS            = \
     -I$(top_srcdir)/src                     \
     -I$(top_srcdir)/src/core                \
     -I$(top_srcdir)/examples/posix/platform \
+    -D_GNU_SOURCE                           \
     $(NULL)
 
-
 libopenthread_posix_a_SOURCES             = \
     alarm.c                                 \
     logging.c                               \

examples/posix/platform/radio.c

@@ -482,7 +482,7 @@ int radioTransmit(void)
 {
     struct sockaddr_in sockaddr;
     int rval = 0;
-    int i;
+    uint32_t i;
 
     memset(&sockaddr, 0, sizeof(sockaddr));
     sockaddr.sin_family = AF_INET;
@@ -564,7 +564,7 @@ void posixPlatformRadioProcess(void)
 void radioSendAck(void)
 {
     struct sockaddr_in sockaddr;
-    int i;
+    uint32_t i;
 
     s_ack_frame.mLength = IEEE802154_ACK_LENGTH;
     s_ack_message.mPsdu[0] = IEEE802154_FRAME_TYPE_ACK;