depths are now optional in geo.Mesh
Moved GeographicObjects to hazardlib
added validation mechanism to ComplexFaultSurface
renamed '_check_aki_richards_convention' to 'check_aki_richards_convention'
Changed GeographicObjects to use min_distance (i.e. the C speedups if present)
Merge pull request #230 from gem/simplify-hc-rc

Added a class to extract the closest object
Merge pull request #231 from monellid/complex_surf_validation

added validation mechanism to ComplexFaultSurface
added hypocenter longitude and latitude in rupture context object
added strike as param in rupture context object
Merge pull request #233 from monellid/extend-rup-context

Extend rup context
Implementa Fukushima & Tanaka (1990) GMPE for PGA
Fixes error in documents
Merge pull request #234 from g-weatherill/fuku_tana_gmpe

Implements Fukushima & Tanaka (1990) GMPE for PGA
Merge pull request #232 from nickhorspool/master

added NZ specific McVerry et al 2006 GMPE for Asc, SInter, SSlab and Volc
added Bradley2013 GMPE
added Bradley2013 GMPE