Added support for DataMember(Order)

- sorting propertyWriters according to Order on DataMember attribute
- processing DataMember attribute of fields as well.
- added reflection extensions for fields
Added support for DataMember(EmitDefaultValue)
Changed the code to minimize side effects
Merge pull request #362 from pavelsavara/DataMemberOrder

DataMemberAttribute - Order, EmitDefaultValue
Proper serialize of x implementing IEnumerable<T>
This commit fixes an issue whereby child items of a class
implementing IEnumerable<T> would not get a __type field,
thereby making it impossible to deserialize the output.
The fix moved code that was meant to run on top of IEnumerable<T>
instances to a place where it will be checked in all circumstances.
Previously it would only be called when an object implements
IDictionary<K,V>
Merge pull request #363 from flq/polymorphic_dto

Proper serialization of an object implementing IEnumerable<T>
INCR to v3.9.58
Fixed to build as SL5 project
Conversion of array of strings to uppercase moved to separate method
Merge pull request #364 from fhurta/master

Fixed to build as SL5 project
remove un-necessary comment
Added InvariantCulture to ParseStringDelegate for numerics. We had an issue with xamarin/monodroid where negative numbers in parsed json-strings was returned as 0. This only happened on devices where language was set to something else than English. This commit fixes that problem.
Merge pull request #365 from Discobanan/master

Added InvariantCulture to ParseStringDelegate for numerics.
Add AppendUrlPathsRaw - like AppendUrlPaths but doesn't encode its parts
ignore invalid culture tests
INCR to v3.9.59
append the "+0000" offset to utc dates if specified
Merge pull request #367 from niltz/master

append the "+0000" offset to utc dates if specified
Prevent MethodAccessException in assembly name retrieval for Silverlight
Merge pull request #368 from x-cray/master

Prevent MethodAccessException in assembly name retrieval for Silverlight