Fixes for cmake on Windows

This pull request addresses several issues with cmake on windows:

1) make install is broken, because there is a macro (add_dll_files) using outdated paths with fixed dll filenames like "${Boost_LIBRARY_DIRS}/boost_regex-vc90-mt-1_38.dll". Once you have a different boost version make install fails.

2) FindOpenEXR.cmake and FindIlmBase.cmake did not take the newest library names of OpenEXR 2.1 cmake builds in account (IlmImf-2_1.lib)

3) Current cmake windows installations do not find newest versions of png and jpeg library, because the names of those have changed, so I augmented the find files.
Again, this is a naming issues, which was introduced by libjpeg's cmake configuration. The change here is trivial and only concerns line 27:

set(JPEG_NAMES ${JPEG_NAMES} jpeg) becomes set(JPEG_NAMES ${JPEG_NAMES} jpeg libjpeg)

I will try and get this merged upstream in cmake, but that could take a while until the next release. If you don't feel well about including this file, we can still wait for that.

Concerning FindPNG, please disregard that file once you merge, I just found out that the issues with libpng have been fixed in the offical cmake version released yesterday.