increment size with image count

This commit adds functionality to the loading callout in the imgur
module.

The size of the font used in the loading callout now increases in a
linear fashion in proportion to the number of images viewed in a row.

The size starts at 12px, and will increase to 72px at image 2000, with
round figures at most "standard" font sizes.

This is largely an experiment to see what it looks like: it might not be
as nice looking now that the callout contains extra information (such as
the view count). It may be worth experimenting with just increasing the
count number and leaving the "a w with x views (y*z)" message at a
static size, or perhaps by editing the colour variant, or even the
position on the screen.

I really just wanted some feedback to make it a bit more interesting for
a heavy user that has reached high numbers of images.

Some figures:
 * 12px is reached after 0 images
 * 14px is reached after 66 images
 * 16px is reached after 133 images
 * 18px is reached after 200 images
 * 21px is reached after 300 images
 * 24px is reached after 400 images
 * 36px is reached after 800 images
 * 48px is reached after 1,200 images
 * 60px is reached after 1,600 images
 * 72px is reached after 2,000 images
 * 144px is reached after 4,400 images.
Add new "details" box to random imgur page

This commit adds a new box to the imgur page, separating the
"Loading..." box with a new "details" box, which contains the
information found via the API.

The loading box appears on the left, and disappears when an image is
loaded, to be replaced with a box on the right.

API operations, such as a "report" or "submit to gallery" option, could
appear below the current right-aligned box, in a smaller font.

I'm undecided as to whether this commit is an improvement or not.
move css around

This commit moves the font-size declaration from the common box CSS to
only affecting the "loading" box.
improve imgur module

* Added config.json to the party
* Moved API key (client ID) to the configuration file
* Added image link to random imgur image page
* Minimised loading message
* Added fade to loading message
* Added count to title attribute of webpage
* Removed font-size increase
* Added placeholders
recommit api key
merge