Fixed a bug where text would disappear in password fields.

There were two bugs:

- First, we need to avoid triggering the CancelTransaction call when
  committing the temporary preedit text, because otherwise FEP starts
  sending us spurious backspace events. Since the
  "triggeredBySymbian" variable is no longer descriptive for that use
  case, I renamed it in the process and that changed the negation of
  the flag. Notice the absense of a change inside
  commitTemporaryPreeditString(). That is because we want that one
  to avoid the transaction cancel, and therefore wee keep the old
  negation.

- Second, m_cursorPos needs to be kept in sync with the widget state
  when we send the temporary preedit string, because the input
  context cannot separate between types of preedit text when it hits
  the first block in commitCurrentString() (types being either our
  temporary text, or FEP's text), and we have to avoid the longPress
  code path.

RevBy:    Janne Koskinen