A list of lists that has information for use in the RavenR rvt-related files.
Additional information on Raven variables can be found in the Raven User's Manual, available from http://raven.uwaterloo.ca/Downloads.html
rvn_rvt_mappings_data
is a list with four lists.
list: data formats for all rvt file types
list: data types permitted in Raven, and associated units
list: meteorological forcing functions permitted in Raven, and associated units
list: mapping of weathercan variable names to Raven variables
rvn_rvt_read
for reading in rvt files
rvn_rvt_write
and rvn_rvt_write_met
for writing data to rvt files.