2.6.15

• Added entries - a key/value store for storing simple strings and numbers in a naryn database. See emr_entries.ls, emr_entries.get, emr_entries.set, emr_entries.rm and emr_entries.reload.
• Added string_to_var and var_to_string functions to generate valid variable names from strings.
• emr_track.rm can now accept multiple tracks as input.
• Do not allow importing patients that do not appear at patients.dob.
• Fixed issue #83
• Fix: emr_track.rm returned an error when given character(0).