add option to build PDAL using static runtime libraries on Windows

This amounts to specifying /MT rather than the default /MD. Also,
Boost can be found more easily (for non-embedded users) by specifying
options up front.
compile time improved on MSVC with /MP flag
start using nanoflann for the soci loader to reorganize within-patch points as a kdtree
Merge branch 'chambbj-use-static-runtime'
Merge branch 'master' into chambbj-add-mp-support-for-msvc