Preparing for maintenance release -

Preparing for maintenance release -
Bug fix - issue introduced in V8.2.2 when the current timer list is empty and the overflow timer list is not empty.
Add PIC32MZ EF (floating point) support and update the MZ demo project to test the flop context switching.
Improve efficiency of the stack overflow checking.
Add CLI to RX71M demo.
General tidy up of new RZ and RX projects - including ensuring the UART driver copes with 0 length strings.
Add stack overflow checking to the [old] PIC24 demo.

git-svn-id: https://svn.code.sf.net/p/freertos/code/trunk@2388 1d2547de-c912-0410-9cb9-b8ca96c0e9e2