src - The source files, subsystem headers/implementations, umbra headers,
	and internal modules

ext - external libraries and dependencies needed for building umbra. They
	don't make part of umbra itself.

lib - Umbra libraries, in C/C++ or umbra code.


Module letters (and prefixes)
	# Utility modules
	Z - [zio] File/Stream I/O, String functions, Character conversion
		ctype, string, sbuffer, buffer, file, cconv
	R - [re]  Regex
	M - [mem] Memory management
	O - [obj] Object definitions
	J - [gc]  Garbage collector (J for junk)
	S - [sys] Operating System utilities
	N - [num] Numbers (Integers, Floats, Complex, Matrices, Long numbers, Math)
	H - [hsh] Object hashtable implementation (array/map, methods)
	G - [dbg] Debug interface
	K - [cls] Default Umbra API interface declaration

	# Pipeline modules
	L - [lex] Tokenizer/Lexer
	Y - [prs] Parser/AST Transformation
	C - [cc]  Compiler/Bytecode definition
	D - [dd]  Dumper/Loader
	V - [vm]  Virtual machine execution/Opcodes declaration


number
	integer
	float
	complex
	ratio
	matrix
stream
	string
	file
regex
bool
object
function
	method
	lambda
	block
	continuation
	iterator