Implement comment reader but disable it since
compiler forms need to support it first.
Fix few inconsistencies in readers read function.
Improve REPL support for multi-line inputs.
Add support for `()` form as a sugar to `'()`
Export non-private symbols by default.
Improve REPL further to allow access to last
3 forms read.
Make wisp type definitions more tolerant to multiple JS contexts.

It's just to easy in node to end up with multiple
js contexts. Also helpful when loading from wisp
files or compiled js files.
Version 0.6.0