Add support for parsing 2 digit years, with a sliding window 70 years back
Write datetime parser in terms of the date and time parsers
Expand the date and datetime parser with more acceptable inputs
Convert the ambiguous date parsing to two parameters

an order: no_ambig, ymd, mdy, dmy
century_window: 0 means no 2 digit year,
                1-99 means sliding window
		1000 and up means fixed window
Put date_parse_order and century_window in the evaluation context
Fixes getting the eval_context for date processing through the system
Merge pull request #20 from mwiebe/datetime

date/datetime parsing improvements, evaluation context date parsing params
Use feature macros for C++11 in clang
Don't use has_extension, just use has_feature
Also check for initializer_list header with generalized initializers
Add <utility> header for std::move
Disable std::move usage on clang because of a bad configuration on OS X
Fix for OS X
New foreach branch
Started reimplementing foreach with metaprogramming
Added a new macro, DYND_PP_OUTER, to the preprocessor
Fix for preprocessor list.hpp
Implemented preprocessor macros more convenient for code generation
Minor fix for GCC
Extended testing