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

[SVN r39108]
first change: pimpl fully applied to IOStreams file_descriptor, tested on linux/gcc-4.1.2

[SVN r39109]
fixed special constructor definition for Windows platform

[SVN r39111]
extended test suite for error testing in IOStreams, tested on windows/msvc8express

[SVN r39180]
minor modification of test cases in IOStreams error_test.cpp

[SVN r39182]