Lots of GDAL3 work

Move OGR::GeometryMixins::Extensions#is_3d? to OGR::Geometry

Fix nil return value from OGR::GeometryMixins::Extensions#utm_zone wh…

…en spatial_reference is not 4326

DEV-37044 Fix requires for lib/*/extensions.all.rb

DEV-37044 Fix NoMethodError in OGR::GeometryMixins::Extensions#utm_zo…

…ne when geometry is invalid

Party time!

DEV-34269 Ensure GDAL::RasterBandClassifier#equal_count_ranges return…

…s a range when only one is requested

DEV-20059 Ensure GDAL::RasterBandClassifier#equal_count_ranges has a …

…minimum spacing between breakpoints

DEV-34133 Don't URI.parse path in GDAL::Dataset#initialize and OGR::D…

…ataSource#initialize

Merge pull request #42 from agrian-inc/DEV-20247

DEV-20247 Fix return value for OGR::LayerMixins::Extensions#point_val…