Starting work on new buildcell framework.
Merge branch 'master' into new_buildcell

Conflicts:
	lib/spipe/lib/sslib/include/utility/MultiRange.h
First version of sslib with completely changed build_cell framework.
Still needs more work but it's a lot better than before.

Everything that relies on sslib still needs to be updated to use it so
these parts don't work yet.
Changed events to use RunnerAccess rather than the runner itself.  This
makes more sense.  Removed corresponding methods in Runner and some
typedefs.
Updated sslib to use new build_cell framework correctly.
Removed PipeRunnerStateChanged event as events are all together now in
PipeRunnerEvents.h
Updated to use new sslib build_cell framework.
Updated to use new sslib build_cell framework
Ignore rule was causing contents build_cell folder in sslib to not be considered for versioning.  Corrected now
Minor change to .gitignore
Fixed few typedef problems etc. preventing build
Fixed problem with using the wrong filesystem namespace which caused compilation with old boost to fail
A bit of work on SeedStructures block, updating to use new ResourceLocator s
Updated build_cell StructureBuild to contain AtomExtruder and some other
small tweaks