synchronized compiler.h

Remvoe std_readline().  This called up_getc() and up_putc() directly, violating the POSIX OS interface.

examples/ostest: Add some delays to the pthread cancellation test.  With deferred cancellation enabled, things happen more asynchronously

examples/ostest:  Extend the pthread cancellation test to exercise pthread_cleanup_push() (and pthread_cleanup_pop() indirectly via pthread_cancel() and pthread_exit()

Remove BOARDIOC_CAN_INITIALIZE.  CAN initialization is now done in the board initialization logic just like every other device driver.

Import patch to fix:cJSON_PrintUnformatted() behaves unexpected if an empty array shall be printed to text. from Jerome Lang 2012-04-19

The examples/qencoder app was trying to init the encoder by a direct call into the board, cheating in a local header to declare the normally unavailable function prototype.