creating new temporary branch for development and testing a non-trivial change

SVN-Revision: 39108
first change: pimpl fully applied to IOStreams file_descriptor, tested on linux/gcc-4.1.2

SVN-Revision: 39109
fixed special constructor definition for Windows platform

SVN-Revision: 39111
extended test suite for error testing in IOStreams, tested on windows/msvc8express

SVN-Revision: 39180
minor modification of test cases in IOStreams error_test.cpp

SVN-Revision: 39182