Added posibility to change settings db via command line for multiple instances (#247)

cps/cli.py

@@ -0,0 +1,21 @@
+import argparse
+import os
+
+parser = argparse.ArgumentParser(description='Calibre Web is a web app'
+                    ' providing a interface for browsing, reading and downloading eBooks\n', prog='cps.py')
+parser.add_argument('-p', metavar='path', help='path and name to settings db, e.g. /opt/cw.db')
+parser.add_argument('-g', metavar='path', help='path and name to gdrive db, e.g. /opt/gd.db')
+args = parser.parse_args()
+
+generalPath = os.path.normpath(os.getenv("CALIBRE_DBPATH",
+                        os.path.dirname(os.path.realpath(__file__)) + os.sep + ".." + os.sep))
+if args.p:
+    settingspath = args.p
+else:
+    settingspath = os.path.join(generalPath, "app.db")
+
+if args.g:
+    gdpath = args.g
+else:
+    gdpath = os.path.join(generalPath, "gdrive.db")
+