Initial GRAN.

Some NOTES will need to be cleaned up in next release:

NOTE
resampleUVdata: warning in as.difftime(time.step, unit = "mins"):
partial argument match of 'unit' to 'units'
loadReg: no visible global function definition for 'shiftData'
loadestTadj: no visible global function definition for 'dectime'
plot.loadReg: no visible global function definition for 'dectime'
predConc: no visible global function definition for 'month'
predConc: no visible global function definition for 'year'
predConc: no visible global function definition for 'daysInMonth'
predConc: no visible global function definition for 'waterYear'
predConc: no visible global function definition for 'leap_year'
predLoad: no visible global function definition for 'ceiling_date'
predLoad: no visible global function definition for 'floor_date'
predLoad: no visible global function definition for 'month'
predLoad: no visible global function definition for 'year'
predLoad: no visible global function definition for 'daysInMonth'
predLoad: no visible global function definition for 'waterYear'
predLoad: no visible global function definition for 'leap_year'
resampleUVdata: no visible global function definition for 'floor_date'
resampleUVdata: no visible global function definition for
'ceiling_date'
resampleUVdata: no visible global function definition for 'days'
resampleUVdata: no visible global function definition for
'mergeNearest'
setXLDat: no visible global function definition for 'dectime'