Script `scratch` and `session` (connect psql to model_scratch and model_sessiondata_

[rburghol]

• Located in /usr/local/bin (to install copy from /om/sh/)
• Use: scratch and session to establish a psql connection to the local modeling databases model_scratch (runtime + runoff cache) and model_sessiondata (legacy postgres imported logfile CSVs for analysis in psql).

attn: @COBrogan