Fixed some issues related to TRIGGER_BY_MRI_SCANNER == 1.

Added FMRI_TA field to expt_config.txt

	modified:   mcode/UIRecorder.m
	modified:   mcode/read_parse_expt_config.m
	modified:   mcode/runExperiment.m
Centered the word display for fMRI runs.
Changes related to the fMRI versions, and others

1. Added tracked example expt_config files

2. Added fMRI scanner trigger key to expt_config.txt

	modified:   mcode/UIRecorder.m
	renamed:    mcode/expt_config.example.txt -> mcode/expt_config.example_fmri.txt
	new file:   mcode/expt_config.example_pitch.txt
	modified:   mcode/genRandScript.m
	modified:   mcode/read_parse_expt_config.m
	modified:   mcode/runExperiment.m