Handle TCODK_NONE in wait_for_keypress correctly

Closing the window while waiting for a keypress will cause libtcod to return a
key type of `TCODK_NONE`.

This should be handled correctly instead of panicking. I don't even know why the
assert was there in the first place.

Fixes #28
Merge pull request #38 from tomassedovic/fix-28

Handle TCODK_NONE in wait_for_keypress correctly
Refer to the enum variants correctly

Enum variants are now by default scoped under the enum name itself.
Remove duplication in Console variant names

This renames `Console::RootConsole` to `Console::Root` and
`Console::OffscreenConsole` to `Console::Offscreen`.

The re-exported root console is still under `tcod::RootConsole` for backwards
compatibility and clarity.
Remove duplication in PathInnerData variants
Remove the `key_code` and `background_flag` modules

The reason we had them in the first place was not to pollute the tcod module
with all the enum variants. Now that they're scoped under the respective enums,
that's no longer necessary.

This is a breaking change.
Bump tcod-rs to version 0.2.0

Just to make the breaking changes a bit more apparent.
Merge pull request #39 from tomassedovic/namespaced-enumps

Namespaced enums
Added set_window_title()
Added missing parameters to set_custom_font()
set_custom_font(): use an array parameter instead of vector
Clear the unused_parens warning
Use the bitflags macro where appropriate

Some of our enums weren't supposed to be enums at all since their values could
be mixed and matched.

This replaces `FontFlags` and `KeyPressFlag` enums with `bitflags!` macros.
These define values that can be joined together.

This is a breaking change. You should change code like this:

    Console::set_custom_font(font_path, &[LayoutTcod, TypeGreyscale])

to:

    Console::set_custom_font(font_path, FONT_LAYOUT_TCOD | FONT_TYPE_GREYSCALE);

And:

    Console::check_for_keypress(KeyPressedOrReleased);

to:

    Console::check_for_keypress(KEY_PRESSED | KEY_RELEASED);

(or any other combination you need)

Closes #40
Bump the version to 0.3.0
Convert tabs to spaces in example1
Move the character using cursor keys in example1
Rename example1 to keyboard

Closes #3
Add example showing text output & alignment

Closes #2
Merge pull request #43 from tomassedovic/moar-examples

Moar examples
Merge pull request #42 from tomassedovic/fix-40-bitflags

Use the bitflags macro where appropriate