Add some simple cube-shaped block definitions
Fixed Windows build

I did the following things:

 * Added libz as a library that needs to be linked. (Failed without)

 * Renamed .def that weren't Windows .def files to .cdef, to avoid
   possible disaster.

 * Made it use "oil.pyd" instead of "oil.so" on nt systems.

 * Added -Wl,--export-all-symbols to the oil build as it would only
   export the module init function on Windows without this option.

 Now builds with mingw-w64 for me.
Fix texture rotation on cube top faces, fix craftign table
Add block defs for dispensers, droppers, furnaces, pumpkins and jackolanterns
Merge remote-tracking branch 'counterpillow/winbuild' into oil
fixed forward declaration, removed --export-all-symbols on posix
output format restructuring, save/save_ex now take a format argument
Add block definitions for slabs, pressure plates, and daylight sensors

make_box now takes two additional optional keywords (bottom and height)
which can control the y-dimensions of a cubething
Add output_* to .gitignore (which is where i often render stuff to while developing)
Merge remote-tracking branch 'origin/oil' into oil
Added carpet, hardened clay, and coal
added jpeg reading/writing to oil, tileset
added MASKED blockdata type, for leaves
mipmapping for cpu renderer
added wxwidgets-based interactive renderer
more UI elements for the map explorer
try to sort of preserve the current view when changing projections
removed executable bit from wxexplorer
added automatic reloading to wxexplorer when pyinotify is present
live code reloading now looks a little nicer