Remove RETAIN qualifier for F_TRIG and R_TRIG 'M' variable. This is not following standard, and implicitely consumes a lot of RETAIN memory. User can explicitely qualify R_TRIG of F_TRIG instance as RETAIN if needed.

iec.flex.c
iec.y.output
iec.y.cc
iec.y.hh
Makefile.depend