Checkbox calls toggleLabelsShow() in jcontrol.js

--------------------------------------------
LABELS OCCUR:
S-,D,X,? labels
Sequence Number / Residue Names
Contacts: labelContacts
SSBonds all Cys
Ends
Crosslinks


VARIABLES
labelsOn // For S-,X,? labels:
labelsFront
labelsID
labelSequenceNumbers
labelResidueNames3
labelResidueNames1

I have used 'set fontsize' instead of 'font labels ...'.

see toggleLabelsShow() used in jcontrol.js for xtlConNow/unitCellNow

see resetLabelCheckboxes() in jcontrol.js

code for selecting *.c5' in nucleotides that don't have phosphorus is at
the end of the script in makeCrystalConSpt() in scripts.js.

Execution:
	in scriptToJmol() in top.js which calls
		 makeMarkContactsTargetSpt()
		 makeLabelSSBondsSpt() // defines ~labeledCys
		 makeLabelsSpt() in top.js
				which calls
					makeXNonStandardResiduesSpt()
					makeMarkAnomalousAtomsSpt()
					makeMarkIncompleteSidechainsSpt() in scripts.js
					and
					makeLabelAllSpt() in scripts.js # SeqNums, ResNames
						which selects atoms to be labeled, excluding S-/X/? and ~labeledCys, then calls
						makeAllLabel() in scripts.js (also called by incomplete and nonstandard)
							which constructs the label string.

makeLabelsCheckboxes() in controls.js

toggleLabelsShow() in jcontrol.js
toggleLabelsFront() in jcontrol.js
toggleLabelsID() in jcontrol.js
toggleLabelSequenceNumbers() in jcontrol.js (toggleSequenceNumbers)
toggleLabelResidueNames3() in jcontrol.js
toggleLabelResidueNames1() in jcontrol.js

checkbox name is cklon