Merge pull request #9 from cmarmo/master

Bug on red/green/blue colormaps fixed. Adding colormap inversion functio...
Changes to IIPImage class contstructors to use more efficient member initializer lists, which are also necessary for compilation with clang compiler.
Plus minor cleanups to IIPResponse.cc and SPECTRA.cc
Changes to IIPImage, TPTImage and KakaduImage class contstructors to use more efficient member initializer lists, which are also necessary for compilation with clang compiler.
Updated hash map definitions to try to use unordered_map if available and fall back to hash_map or map. Now done more cleanly using autoconf detection.
Another update to use the ISO C++11 version of unordered_map if available. Plus a bunch of compiler warning clean-ups.
Minor fixes to PFL.cc to add extra error checking and eliminate compiler warnings.
Very small Min Max bug fixed. Some new timing added.