memory: moved global functions below Allocator to better match flow in .cpp.
math: added interface header, corrected includes for math_types.

test/general/headers: added math.hpp.
test/.gitignore: added test binaries.
debug_constraints: added TOGO_CONSTRAIN_SAME(T, U).
hash: added interface and literal test.
doc/pages/math.dox: added note on lack of documentation for math operations.
assert: added debug-message macros; restyled error & debug messages.
debug_constraints: added TOGO_CONSTRAIN_INTEGRAL(T) and TOGO_CONSTRAIN_ARITHMETIC(T).
Added #line markers to all source files to make reporting less verbose; added missing @copyright headers.
utility: new header; added signed_cast(), unsigned_cast(), min(), max(), pointer_add(), and pointer_align().
memory: added JumpBlockAllocator, TempAllocator, and TempAllocator test.