Add writing of .v3draw format for easy loading with Vaa3D.

Vaa3D (http://vaa3d.org ) is an open-source program for 3D
visualization and analysis of bioimage datasets.  .v3draw is a
minimalist format designed for rapid writing and reading with Vaa3D,
currently supported by Fiji for reading and writing.  This commit
provides .v3draw writing capability for bioformats.
Correct issues brought up by @melissalinkert

See pull request for content. Most substantive change: V3DrawWriter
class now takes endianness of file from metadata and writes the .v3draw
file  with the same byte order as the input.
Specify encoding when working with strings

This fixes warnings reported by Findbugs in
http://ci.openmicroscopy.org/view/Failing/job/BIOFORMATS-5.1-merge-build/352
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.
Merge pull request #1 from melissalinkert/findbugs-fix

Specify encoding when working with strings
cpp: VariantPixelBuffer: Change spelling of docstring
cmake: Correct typo restoring required includes

Thanks to Ian Munro for spotting this!
FindXerces: Correct sphinx markup for section heading
merge develop -Dorg -Ssuccess-only: PR 978 (Add writing of .v3draw format for easy loading with Vaa3D.)
merge develop -Dorg -Ssuccess-only: PR 1154 (Leica: prevent exception when linking EmissionFilter)