ColorCodes: simplify and comment a bit.

- Simplify logic and increase explanation to make it easier
  for the casual reader.
- Remove the undocumented, untested and not-clearly-working
  "percentage" support.
- Replace `eval` with `try`, as is my wont.

Addresses #620.
ColorCodes: allow for rgb #123456-style queries
ColorCodes: rough in a different HTML template.

Real templates are coming, but this is a step.
DateMath: properly recognize and handle weeks.

Fixes #628.
Merge pull request #629 from mwmiller/date_math

DateMath: properly recognize and handle weeks.
Merge pull request #625 from mwmiller/color_sanity

ColorCodes: simplify and comment a bit.
Move goodies to new styling mechanism.

- Rename 'style.css' to appropriate ID-based name.
- Remove explicit inclusion of CSS, as it will now be auto-included.
- Update tests which explicitly checked for styling.
SHA: move from inline CSS.
ValarMorghulis: move from inline CSS.
Dice: move from inline CSS.
Unifornify: move from inline CSS.
UltimateAnswer: remove trailing whitespace.
UltimateAnswer: move from inline css
ColorCodes: move from inline css
ResistorColors: move from inline CSS.
ColorCodes.t: test to see if we styled in the correct background.

With the full test below of where the background styling takes place,
this should be sufficient to ensure that we haven't made any wildly
wrong code changes.
ResistorColors/ColorCodes: update new selector names.

Changed to be a bit less generic at the behest of @russellholt
Merge pull request #630 from duckduckgo/mwmiller/easier_css

Goodie CSS Changes.
UnixTime: update output to include the epoch.

This is in service to some submarine commits which will be arriving soon
to deal with Goodies templating.  This makes UnixTime look "more like it
will" in addition to supplying what we determined to be the supplied
epoch.

This is most useful in the "empty" epoch case where we will tell them
the current epoch which may be of interest.
UnixTime: remove `time` trigger.

This eliminates the conflict with the preferred W|A answer.

Addresses #607.