intrepid navigators

rb3 0.0.6

• Updated documentation
• functions code2month and maturity2date now accept old 4 characters maturity code, before 2006
• New function cotahist_options_by_symbol_superset joins options data, equity data and interest rates for each option for a given symbol (Issue #50)
• Corrected BUG in cache system, avoid caching NULL returns (Issue #52)
• Corrected BUG cdi_get and idi_get use do_cache = FALSE (Issue #51)