_it_mask() and _it_restore() functions now share a global array indexed
by the proc_id (used a simple global variable before => problem with
multiproc)
added 2 new fuctions _it_enable() and _it_disable() that only affect the
IE bit of the status register in COP0
replaced interrupt masking/restoring arround _ctx_switch() in sys_handler
by a simple interrupt disabling before the call to _ctx_switch (restoring
after a _ctx_switch wouldn't restore the correct task's status register)
replaced the use of _ctx_switch in _exit() by a call to _context_switch()
(this function actually does the interrupt disabling)
Added some comments in the ctx_handler.h
Added the delay reset in the idle task (ctx_handler.c)
Added a new irq type (PTI)
Modifications in xml_parser.c to accept PTI irq type (now used in xml
mappings)
Added the test on the irq type in the _irq_demux() function. This leads
to a different argument passed to the ISR (i.e. either channel_id or
irq_id (aka icuid) )