that none of it persists for long.
This isn't always true - for example a long running .for loop.
Buf_DestroyCompact() is used by Var_Subst(), rather than Buf_Destroy().
If it looks like we can save BUF_COMPACT_LIMIT (128) or more bytes,
call realloc. This can reduce memory consumption by about 20%
Setting BUF_COMPACT_LIMIT to 0 dissables this.
Saves having to malloc/free a fixed size structure.
Buf_Init() now takes ptr to Buffer to initialiase.
Change Buf_Destroy() to return ptr to string when not freed.
Remove large number of casts to (Byte) and (Byte *) - 'Byte' is 'char' here.
Buf_AddByte[s] guarantees that the data is 0 termininated, so never add '\0'.
Keep 'count' not 'left' and 'inPtr', code is simplier with only one update.
Fix fallou, no functional change.
Replace Buf_Discard() with Buf_Empty() since the former might leave the
'outPtr != buffer' and the only caller wanted all the data discared.
Remove 'outPtr' now that it always equals 'buffer'.
The assumption about Buf_GetAll()is now guaranteed by design.