Big syntax and roxy overhaul. 

Major mods to get_temp methods, that are more accurate for bottom temp extractions. Haven't tested all cases that were covered by current master of rGLM. These include 0 size .nc files, and dried up lakes etc.

@lawinslow I am going to keep this open until my syntax overhaul is complete. Just wanted to give you a heads up as to what the changes look like. 
Those are actually pretty useful. At least in certain situations. It is nice, algorithmically, to not need to have an external source of information for bth.