sim_core: add ldi, labeling corrections.

in moving the majority of instructions to follow use of register
 macros, ldi was missed.

get_h4_k16() was incorrectly labeled where get_h4_k8() was intended
 as k is an 8 bit quantity not 16.

get_o_12() was changed to get_o12() following the convention set
 forth with the other macros.

several trace statements were missed during the conversion and fixed.

ORI was incorrecly labeled as ANDI in the description and corrected.

	modified:   sim/sim_core.c
sim_core: flag equations refactored.

Most flag equations have been refactored into flag group function
  blocks...  The core passes all provided tests in the tests folder
  and now most especially is able to pass the instruction test code.
  At the same time, the overall average cycles per instruction has
  ticked down.

	modified:   sim/sim_core.c
Merge pull request #69 from bsekisser/master-core-ldi-labeling-misc

sim_core: add ldi, trace and labeling corrections.
Merge pull request #67 from bsekisser/master-core-refactor-flags

sim_core: flag equations refactored.
avr_timer: refactor avr_timer_write and avr_timer_reconfigure

avr_timer_reconfigure: calculations moved back in call chain to
 avr_timer_write.

avr_timer_configure: use data processed in avr_timer_write.

avr_timer_init: changed to fully trap writes going to as2,
 clock select bits and waveform generation mode bits.

	modified:   ../../simavr/sim/avr_timer.c
	modified:   ../../simavr/sim/avr_timer.h

avr_timer: remove as2 timer check.

	modified:   avr_timer.c