This allows macros to take a keyword dict containing useful things by
defining a keyword argument. This allows us to pass in new objects
which might be handy to have in macros.
This changeset refactors module_name to become `compiler`, so that we
can pass the compiler itself into the macros as `opts['compiler']`.
This allows the macro to both get the macro name
(`compiler.module_name`), as well as use the compiler to build AST.
In the future, this will enable us to create "super-macros" which return
AST, not HyAST, in order to manually create insane things from userland.
For userland macros (not `defmacro`) the core.language `macroexpand`
will go ahead and make a new compiler for you.
Added first iteration of reader macros
Refactored defmacro and defreader
Added test inn hy/tests/lex/test_lex.py
Added new test in hy/tests/native/tests
Added new test in hy/tests/macros.
changed the error given in the dispatch macro and added some handling for missing symbol and invalid characters
