Intermediate checkin, layers generalization, image slice utils
- Models:
  begin using
    p.sprout 1 for p in @patches.nOf(@population)
  rather than create agents and random x/y
- Util
  ctxTextParams->elementTextParams generalize to DOM elements
  add insertLayer for creating more layers for model
  add imageSliceToCtx for creating ctx from part of image
  factor createLayer to use insertLayer
- DataSet
  imageRowsToData added as class method; experimental
- Model
  Generalize layers to dom elements; add Image layer
Update for Tracer project
- DataSets
  - add toContext, convert toImage to use it
  - toPatchColors/toDrawing: add rest of image args, defaulted
  - toPatchVar: if length is patchs length, don't sample
  - added convolution utilities for: dzdx, dzdy, laplace8, laplace4
  - PatchDataSet: add arrayType for typed array usage
  - ImageDataSet: use util imageToData* procs
- AgentSet
  - own(vars): vars can be array of strings or string w/ spaces
  - add generalized floodfill
- AgentSets
  - Patches: use setCtxSmoothing utility
  - Patches: add floodfill override with p.n as neighbor function
  - Patch: add patchAt dx, dy
- Model
  - @div: now is html element, rather than element id string
- Util
  - add tls (toLocaleString) .. good for comma-readable numbers
  - add firstOneOf in array
  - uniq: no-op if a.length<2
  - aMax, aMin, aSum: convert from "reduce" to work with typed arrays
  - add image data methods:
    cloneImage, imageToData, imageRowsToData, pixelBytesToInt, pixelByte
  - imageToCtx: update to scale image if width,height given
  - ctxToImage replaced by ctxToDataUrl and ctxToDataUrlImage
  - removed unused canvasToImage, canvasToImageData, imageToCanvas, copyCtx
- Models
  - HTML title now model's name
- Cakefile
  - add git diffs for source and models
Oops; added back copyCtx
Add index etc for GitHub pages use
Add index etc for GitHub pages use
Bug fix: data.toPatchVar
add CNAME
xhrLoadFile: add GET/POST param, update all calls
Add droplets GIS model
Add droplets GIS model
Color based updates, plus misc fixes/updates
util:
  - add randomSeed which raplaces Math.random with a seedable generator
  - colorStr: error check for alpha > 1 (i.e. 0-255 check)
  - rgbToHsb: return h,s,b in 0-255, not 0-1
  - hsbToRgb: input h,s,b in 0-255, not 0-1
  - sortBy: prop replaced by more general function, defaults to prop if string.
mouse: adjust to div being element, not name
models: test randomSeed
util: added 4 olormap generators
rm gitignore, update readme
bug fixes, gh-pages updates, include sketches
gh-pages prep: remove CNAME, index.html, tools/js-markdown-extra.js
These will migrate to the new simpler gh-pages
Update README.md to remove older gh-pages kruft
Fix data.js alphs: 0-255 (pixel) vs 0-1 (CSS)
add .htaccess to sketches, fix bug in patch drawing
Fixed patches drawing 1-pixel patches for when individual patches also drawn.
bug fixes (NNMC)
- patches installColors, use identity transform
- model set model.reset's restart=false, i.e. do not assume animator used