added the ylim.trump.interval as another means of influencing ylim, add comments, and some minor adjustments to how emergency backups of the ylim are worked through

updated description of LEV_SRC_CD as we now enforce the 10 levels whether present or not and missing replaced with code U

bug fix on construction of the cv SVM that fails if all data are on the same day, a NULL for the.cvm variable was not being trapped quite right

minor change as a LEV_DT_ACY_CD character back to factor casting needed for some sparse metadata input datasets

updated to leaving creation date within the aREADME.txt files. The aHEADER.txt was already doing this. WHA had a user request this feature.