Fix for #245 - Images no stay on the appropriate plot

Plot was being overwritten for every other plot, every save. After that,
ran into an issue with the login prompt not properly calling back to
load images from every plot, only the one that opened the dialog.
Fix for #212 - Horizontal Resize no longer overlaps plots
Working on #237. Removed the squares from being displayed
More changes to select the nearest image
Added more accurate calculation for first-node distance
Added image selection for plots
Fixed positioning of image control, control width
Fixed bookmarks for image selection
Properly namespace plugin model markings.
Properly namespace mustache context.
Stub-out a plugin model that will use a custom request to do server-side calculation.
First pass at support for custom model handler plugins.
Use PEP-8 naming.
Switch to PEP-8 naming.

Conflicts:
	packages/slycat/web/server/database/couchdb.py
Stub-out a threaded database monitor.
Finish the switch to a generic database monitor object.
Add long-polling to the GET-Projects request.

Conflicts:
	web-server/js/slycat-projects.js
	web-server/templates/slycat-projects.html
The mob has spoken: store css and related content in a "css" folder.

Conflicts:
	web-server/config.ini
	web-server/css/bootstrap-theme.css
	web-server/css/bootstrap-theme.css.map
	web-server/css/bootstrap-theme.min.css
	web-server/css/bootstrap.css
	web-server/css/bootstrap.css.map
	web-server/css/bootstrap.min.css
	web-server/css/slycat-brand.png
	web-server/css/xeditable.css
	web-server/templates/slycat-model.html
	web-server/templates/slycat-project.html
	web-server/templates/slycat-projects.html
Cleanup / simplify configuration files.

Conflicts:
	docker/slycat/config.ini
	web-server/config.ini
Checkpoint work on plugin model resources.