Code Cleanup: Remove trailing spaces
Add a udev rules file to be dropped into /etc/udev/rules.d/

Closes #1
Get rid of magic numbers in demo.py

- Consistently use TextLines.ALL
- Use True/False for booleans passed to display_network_info()
Implement a hack to allow coloured two-column text.

- Add support for limiting the length of the padding so that, if column 2
  is drawn first, column 1 can be drawn without erasing it.
- Add a COL2LEFT constant for using padding to implement left-aligned
  text in the second column.
Implement faster single-color drawing for two-column text.

(Basically, implement support for the TAB character)

Closes #2
Show ALL the icons in demo.py and adjust the show-icon.py help.

- demo.py was showing only 32
- show-icon.py's help said there were 42
- My tests show there to be 43 (#43 being "night-time thunderstorms")
- My tests indicate that requesting icons up to 48 doesn't cause problems
  so I'll let it do that because it makes things less confusing.
  (And it's possible some devices might actually have icons in slots 44-48)
Spiff up the demo script a bit.

- Use nicer formatting for the code
- Demo a reverse-order incremental clearing of the screen
Incorporate proper wait times into LCDSysInfo to speed up drawing

(The device gets slow if it draws and handles USB traffic at the same time
and it's easy for users to forget to wait in their own program. It already
waits in some commands, so we might as well stay consistent.)
Tidy image-loop.py and show-*.py and use the new large_image_indexes list
Minor formatting adjustment in info.py
Merge pull request #2 from ssokolow/master

No apparent way to draw a two-column layout like in the official photos of the device