CMake: Fix libname handling of OpenEXR 2.1. The library built with Autotools was not found.

Weird library names having version suffix (e.g. libIex-2_1.so) are used only
when the OpenEXR was built with CMake.  Building the library with the Autotools
doesn't add the version suffix.

build_files/cmake/Modules/FindOpenEXR.cmake

@@ -34,6 +34,14 @@ IF(NOT OPENEXR_ROOT_DIR AND NOT $ENV{OPENEXR_ROOT_DIR} STREQUAL "")
   SET(OPENEXR_ROOT_DIR $ENV{OPENEXR_ROOT_DIR})
 ENDIF()
 
+SET(_openexr_FIND_COMPONENTS
+  Half
+  Iex
+  IlmImf
+  IlmThread
+  Imath
+)
+
 SET(_openexr_SEARCH_DIRS
   ${OPENEXR_ROOT_DIR}
   /usr/local
@@ -87,24 +95,7 @@ IF(OPENEXR_INCLUDE_DIR)
   ENDIF()
 ENDIF()
 
-IF(${OPENEXR_VERSION} VERSION_LESS "2.1")
-  SET(_openexr_FIND_COMPONENTS
-    Half
-    Iex
-    IlmImf
-    IlmThread
-    Imath
-  )
-ELSE()
-  STRING(REGEX REPLACE "([0-9]+)[.]([0-9]+).*" "\\1_\\2" _openexr_libs_ver ${OPENEXR_VERSION})
-  SET(_openexr_FIND_COMPONENTS
-    Half
-    Iex-${_openexr_libs_ver}
-    IlmImf-${_openexr_libs_ver}
-    IlmThread-${_openexr_libs_ver}
-    Imath-${_openexr_libs_ver}
-  )
-ENDIF()
+STRING(REGEX REPLACE "([0-9]+)[.]([0-9]+).*" "\\1_\\2" _openexr_libs_ver ${OPENEXR_VERSION})
 
 SET(_openexr_LIBRARIES)
 FOREACH(COMPONENT ${_openexr_FIND_COMPONENTS})
@@ -112,7 +103,7 @@ FOREACH(COMPONENT ${_openexr_FIND_COMPONENTS})
 
   FIND_LIBRARY(OPENEXR_${UPPERCOMPONENT}_LIBRARY
     NAMES
-      ${COMPONENT}
+      ${COMPONENT} ${COMPONENT}-${_openexr_libs_ver}
     HINTS
       ${_openexr_SEARCH_DIRS}
     PATH_SUFFIXES
@@ -121,6 +112,8 @@ FOREACH(COMPONENT ${_openexr_FIND_COMPONENTS})
   LIST(APPEND _openexr_LIBRARIES "${OPENEXR_${UPPERCOMPONENT}_LIBRARY}")
 ENDFOREACH()
 
+UNSET(_openexr_libs_ver)
+
 # handle the QUIETLY and REQUIRED arguments and set OPENEXR_FOUND to TRUE if 
 # all listed variables are TRUE
 INCLUDE(FindPackageHandleStandardArgs)