added ring of death to trap and signal nasty errors, asserts, as an aid to debugging failure

git-svn-id: https://svn.code.sf.net/p/freetel/code/codec2-dev@1833 01035d8c-6547-0410-b346-abe4f91aad63
code to trap and fix buffer overflow issue in USB code that was killing other variables in the sm1000

git-svn-id: https://svn.code.sf.net/p/freetel/code/codec2-dev@1834 01035d8c-6547-0410-b346-abe4f91aad63
moved ring of death ISRs to leds and swicthes driver

git-svn-id: https://svn.code.sf.net/p/freetel/code/codec2-dev@1835 01035d8c-6547-0410-b346-abe4f91aad63