cleaned up function interface to avoid referencing the file system in the worker functions.
replaced StringTable's operators with functions.. The main reason is that these are far easier to look up when browsing the source.
This also fixes a premature translation in SBARINFO that was done in the parsing stage, not the printing stage.
* removed refreshFreq variable and related code. This only got into the backend because of stupid interpolation code in some of the Build games which has long been removed.
* save FixedBitArrays as base64 in savegames.
* allow indirections in the string table - by prefixing the language string with '$$' the remaining text is interpreted as another string label to resolve.
* constexpr in palette code, also replacing #defines with enums.
