Started work on preprocessor
Fixed preprocessor to work for MSVC
Implemented map for the preprocessor
Made preprocessor map work for MSVC
Cleaned up MSVC fixes
Fixes for PP list
Fixed PP elementwise for GCC
Testing different strategies for MSVC bug
Changed syntax for lists to better support MSVC
Added support for nested macros
Fixed comparision operators on Linux
Merged mwiebe's CMakeList changes
Clean up
Merge pull request #24 from mwiebe/pp

Preprocessor for metaprogramming
Change the DEPENDS of ppgen_run custom target so it doesn't rebuild constantly
Convert the rest of the date calculations to use the date_ymd struct
Add handling of monthfirst/dayfirst ambiguous dates
Optimize the month and weekday string matching a little bit
Implement the time type

Biggest missing feature, aside from time zones, is
parsing from strings
Move common functionality from date_parser.cpp into parser_util.hpp/cpp