initial commit - starts refactoring layout
refactors and re-styles nav links in Play. adds tools and Current games
adds chat to homepage and adds flex-shrink to some elements
corrects parameter order of Chat._addMessage
removes y-axis and re-styles x-axis on SeekGraph
adds further explanation of optimisation to README
fixes scrolling on homepage chat box
allows vertical scrollbar on GamePage main container

this solves the problem of wanting scrolling as well as automatic
full-height to make things stretch.  scrolling must be on inner things
as opposed to the whole page, which works well with the layout anyway.

also sets position: relative on the scrolling element so that the board
scrolls with it.
starts merging Play into Lightsquare - lots of loose ends left
refactors css
updates 'no challenges' message on SeekGraph
removes redundant box-shadow: none from div.nav a.on
lightens time brackets on SeekGraph
refactors template updates in Lightsquare and removes unused template property
adds login form
moves Log in button background towards grey and turquoise slightly
implements logout confirmation
removes _router.execute from Lightsquare constructor

it should only be called once the server is connected.
updates nav styles - gray default; blue convex on
sorts out game link hover styles in main nav