drop unused helpid

Change-Id: Iaaa129d1baaab485e9700776182cd8d28b134b88
use ok, cancel, help like everywhere else

Change-Id: Ibc4a5ee29fd9a6e734bef7ab9ce404aa8beaaaac
fix build error

Change-Id: I9db006805bfd457663762e2fd2863d096b2547b4
fallback to DefaultEncoding when eCurrentEncoding is unknown

as seen when saving abi10092-1 to rtf

sal/rtl/string.cxx:186: OSL_ASSERT: pTarget != NULL && (pSource != NULL ||
nLength == 0) && nLength >= 0 && (nLength == 0 || rtl_isOctetTextEncoding(nEncoding))

Change-Id: I638b94041899145f42ecd80982d8e7c0330b35c0