use manifold-core v0.8.0
variable creation and definition no longer requires a type expression
(this did not make sense; most of the time we do not have
that information at the time a variable is defined)
fix: we are not assigning the rvalue when making a variable
sanitize namespace identifiers (fixes #35)
simple type checker: resolve variable references and literal expressions
add simple test case for type-checking
add test case: inferred type through literal
refactor: add analyze(Variable), logging
test: primitive function
function invocation type assignment (WIP)
add machinery for determining the types of function inputs/outputs
Merge branch 'master' into expression-rework

Conflicts:
	src/main/java/org/manifold/compiler/front/NamespaceIdentifier.java
remove duplicate visit() method
remove unnecessary compilation dependency
removed todo; opened #38
remove leftover debugging code
remove todo; opened #39
remove unnecessary todo
remove todo; opened #40
throw exception for unimplemented method; opened #41