Update documentation/hasfocus-binding.md

update "hasfocus" to "hasFocus" to match camelCase convention
Update navigation menu entry for 'hasfocus' to 'hasFocus'
add build to .gitignore
remove broken link to ko.postJson utility documentation, fixes #560
Merge pull request #832 from paglias/gh-pages-2.3.0

fixes #560
Merge branch 'gh-pages' into gh-pages-2.3.0

Conflicts:
	_includes/documentation-menu.html
	documentation/submit-binding.md
Update docs for ko.unwrap; fixes #895
document the beforeChange event
document optionsAfterRender
Merge pull request #915 from knockout/915-gh-pages-beforeChange

Document the beforeChange event
Merge pull request #983 from knockout/983-gh-pages-optionsAfterRender

Document optionsAfterRender
describe using an observable for the template "name" option
fixes #984
describe the "notify" extender
fixes #884
Update specs to 2.3.0
Merge remote-tracking branch 'remotes/origin/gh-pages' into gh-pages-2.3.0
Add 2.3.0 and update download links.
Add 3.0.0beta
Merge pull request #1026 from knockout/gh-pages-2.3.0

Gh pages 2.3.0