cmake: Work with Boost on nonstandard paths
cmake: Add FindXerces
cmake: Add cpp/cmake to cmake module path
cmake: Correct Boost checks and usage
cmake: Use FindXerces
cmake: Correct FindTIFF usage
cmake: FindXerces corrections suggested by upstream
FindXerces: Additional corrections suggested by upstream
FindXerces: Improve version checking
FindXerces: cmake 2.8 portability fix
cmake: Add /bigobj when building with MSVC

This is needed for both bioformats and OmeroCpp so that individual
object files may contain more than 2^16 symbols.
cmake: Correct typo restoring required includes

Thanks to Ian Munro for spotting this!
FindXerces: Correct sphinx markup for section heading
Merge pull request #1273 from rleigh-dundee/cmake-fixes

cmake: Add FindXerces support and correct minor portability problems