tk: Default to OS X GUI and fix wish dylib issue

- pass LIB_RUNTIME_DIR to make
- Default to Aqua GUI since X11 is no longer
  shiped with OS X 10.8.
- Using :optional for :x11 so you can install --with-x11

- Fixes:

  dyld: Library not loaded: ...
    Referenced from: /usr/local/bin/wish8.6
    Reason: image not found
  [1]    86386 trace trap  wish8.6
fix lapack build and install
lapack: 3.4.2
tidy: Add tidy-html5 as --HEAD

This build tidy from the experimental html5 fork which adds support for
validating html5 syntax.

More info:
http://w3c.github.com/tidy-html5/
https://github.com/w3c/tidy-html5/

Closes #150
unzip: really fix quoting