+ Changed the method used to force a context switch within an ISR for the
ARM7/9 GCC ports only. The portENTER_SWITCHING_ISR() and
portEXIT_SWITCHING_ISR() macros are no longer supported. This is to
ensure correct behaviour no matter which GCC version is used, with or
without the -fomit-frame-pointer option, and at all optimisation levels.
+ Corrected the prototype for xQueueGenericSend() within queue.h.
+ Introduced API function xTaskResumeFromISR(). Same functionality as
xTaskResume(), but can be called from within an interrupt service routine.
+ Optimised vListInsert() in the case when the wake time is the maximum
tick count value.
+ Bug fix: The 'value' of the event list item is updated when the priority
of a task is changed. Previously only the priority of the TCB itself was
changed.
+ vTaskPrioritySet() and vTaskResume() no longer use the event list item.
This has not been necessary since V4.0.1 when the xMissedYield handling
was added.
+ Lowered the PCLK setting on the ARM9 STR9 demo from 96MHz to 48MHz.
+ When ending the scheduler - do not try to attempt a context switch when
deleting the current task.
+ SAM7X EMAC drivers: Corrected the Rx frame length mask when obtaining
the length from the rx descriptor.
