Added download.sh and modified .gitignore to ignore data directory

.gitignore

@@ -102,3 +102,6 @@ venv.bak/
 
 # mypy
 .mypy_cache/
+
+# ignore data profiles
+DATA/*

download.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+
+# Download the PHOTOCHEMCAD3 database for the user, will unpack it into
+# the DATA directory (not tracked by github)
+
+URL="http://www.photochemcad.com/download/PhotochemCAD3.zip"
+FLNM=$(basename $URL)
+PREFIX=DATA
+
+#make data directory if needed
+ls $PREFIX 2>/dev/null
+if [[ $? -ne 0 ]]; then
+  echo "Making $PREFIX directory in $PWD"
+  mkdir $PREFIX || \
+  { echo "Unable to create directory, check permissions" && exit 1; }
+else
+  echo "DATA directory already exists, be careful of existing files"
+fi
+
+#Downloading the *.zip archive
+which wget 2>/dev/null
+if [[ $? -eq 0 ]]; then
+  wget -P $PREFIX/ $URL ||\
+  { echo "Unable to download, check internet and try again" && exit 1; }
+else
+  curl -o $PREFIX/$FLNM $URL ||\
+  { echo "Unable to download, check curl installed and internet" && exit 1; }
+fi
+
+#Unzipping the *.zip archive
+which unzip 2>/dev/null
+if [[ $? -eq 0 ]]; then
+  unzip $PREFIX/$FLNM -d DATA || \
+  { echo "Unable to extract, check internet and is zip" && exit 1; }
+else
+  echo "You need to install 'unzip' for this script"
+  exit 1
+fi
+
+#Let user know finished
+echo "PHOTOCHEM archive sucessfully downloaded and unziped"
+exit 0