Added toString() helper
Added basic searchPlugin.
Added default search callback.
Added searchResult renderer
Added styles for .htSearchResult class
Added toString() helper
Added basic searchPlugin.
Added default search callback.
Added searchResult renderer
Added styles for .htSearchResult class
Fixed search plugin tests
Added ability to set custom search result class
Merge branch 'feature/searchPlugin' of github.com:warpech/jquery-handsontable into feature/searchPlugin

Conflicts:
	src/plugins/search.js
	test/jasmine/spec/plugins/searchSpec.js
Fixed omitted conflicts in search plugin and tests
Added ability to define custom query method. The default query method interprets query as string, not as regex. The default query method is case insensitive.
Default query method returns false if query string is empty, is null, has no been specified or is not string.
rename "extensions" to "plugins" for consistency (in code and file paths)
rename to names that better describe class purpose - WalkontableCellFilter => WalkontableAbstractFilter, WalkontableCellStrategy => WalkontableAbstractStrategy
move Handsontable.SelectionPoint => WalkontableCellCoords, add simpler interface (row, col) and isValid method with a spec
- namespace Handsontable.PluginHooks is now Handsontable.hooks
- new methods in Handsontable.hooks: register, deregister, isRegistered, getRegistered (+tests)
- change demo/callbacks.html to use getRegistered
- change the existing plugins to use Handsontable.hooks.register
- remove hooks registered by the plugins from src/pluginHooks.js