Anduin Code

AST for constant expressions is showing signs of life.

Parses basic variable declarations. ('Basic' means 'initialization only works
for constants, not general expressions'.)

Prefix exported symbols with "AN"; fixed command-line filename reporting.

Added bison.hh dependency; added 'clean' target.

Execute argv[1] instead of hardcoding.

Split out each compile separately, just for now.
TODO: compile all .o's the same, create list of file basenames for linking.

First pieces of a proof-of-concept parser.

Adding initial directories.