Main

Additional improvements to the fixed type. Also added a few good test
cases.

Modify template to include parameters for strtoXXX functions. Also begin
integrating support for 128 bit integer types.

Adding int128.h header with support for GCC specific int128_t and
uint128_t types.

Additional improvements to the fixed point type. Also adding parse_test
which can be used to compare parse performance and a CMakeLists.txt.