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1) make install is broken, because there is a macro (add_dll_files) using outdated paths with fixed dll filenames like "${Boost_LIBRARY_DIRS}/boost_regex-vc90-mt-1_38.dll".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.
What if they are using EXR < 2.1?