Templated accessors and range-based for

Editorial changes to schema documentation

Fixed up some wording to the schema documentation

Also remove SetArray|Object(…)

Add (Pretty)Writer::RawValue()

Add Writer::SetMaxDecimalPlaces()

Optimize Writer::WriteString() with SIMD

Fix #205

Add stream position check to reader unit tests

Add Value::Get/SetFloat(), Value::IsLossLessFloat/Double()

Fix #341

Support {0, } and {0, m} in Regex

Add encoding validation option for Writer/PrettyWriter