store: rework to allow for 'init'

Rework the error handling / exception for read-only / writable and new
database.

lib/utils/mu-utils.hh

@@ -94,17 +94,6 @@ std::string format (const char *frm, ...) __attribute__((format(printf, 1, 2)));
 std::string format (const char *frm, va_list args) __attribute__((format(printf, 1, 0)));
 
 
-/**
- * Quote a string -- put in "" and escape any special characters by putting '\'
- * in front of them.
- *
- * @param str
- *
- * @return
- */
-std::string quoted (const std::string& str);
-
-
 /**
  * Convert an date to the corresponding time expressed as a string with a
  * 10-digit time_t