remove useless TwsSocketClient.lib
import IB's TWS API 9.69-4 (969.01)

Now IB has started to give it a version number 969.01. Also they removed
API_VersionNum.txt and changed the directory layout. We will wait a bit
until this seems to be stable before following them.
import IB's TWS API 9.69-5 (969.03)

This is still converted to the old directory layout
update ChangeLog-IB to 9.69 final
revert cpp API downgrade ...

Looks like IB's 969.03 relase was broken. Java and CPP CLIENT_VERSION are not
in sync. So we guess here how it should be correct ... but we are not in sync
with upstream right now.
Merge branch 'ib_orig' into ib_orig_plus

* ib_orig:
  revert cpp API downgrade ...
  update ChangeLog-IB to 9.69 final
  import IB's TWS API 9.69-5 (969.03)
  import IB's TWS API 9.69-4 (969.01)
  remove useless TwsSocketClient.lib